Is i3 6100 a good non gaming CPU? Mom's PC build

What is your budget?
If she does multi tasking and frequently has large numbers of tabs, emails, spreadsheets open as you mentioned briefly, she'll want an i5. She doesn't need a K processor unless she's overclocking, which is almost exclusively used for gaming rigs, no need to introduce extra temps, costs etc. into a workstation machine.
16GB of RAM is only a bit more expensive and allows you to convert it into a video editing/gaming PC if you just chuck in a graphics card, your choice whether you want to go for this.
I've left one slot open for this potential in the future.
250GB SSD for OS, software and some key programs. If you want to save a bit go for the 120GB model, but its only $15 more for twice the storage, so not worth it imo.
SSD is not really necessary, but it greatly improves boot times, so it is a valuable addition in any build in my opinion.
If you want to cut back below the $500 mark, get the Rosewill FBM-02, which is a basic case.
Here is what you should do, i've gone for the 520w over the 430w due to the only $5 difference:
PCPartPicker part list: http://pcpartpicker.com/list/G7Dn7h
Price breakdown by merchant: http://pcpartpicker.com/list/G7Dn7h/by_merchant/

CPU: Intel Core i5-6500 3.2GHz Quad-Core Processor ($199.99 @ NCIX US)
Motherboard: Gigabyte GA-H110M-A Micro ATX LGA1151 Motherboard ($47.98 @ Newegg)
Memory: G.Skill Ripjaws V Series 8GB (1 x 8GB) DDR4-2400 Memory ($32.99 @ Newegg)
Storage: Samsung 850 EVO-Series 250GB 2.5" Solid State Drive ($90.13 @ Amazon)
Storage: Western Digital Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive ($47.49 @ OutletPC)
Case: NZXT S340 (Black) ATX Mid Tower Case ($59.99 @ Newegg)
Power Supply: SeaSonic S12II 520W 80+ Bronze Certified ATX Power Supply ($58.99 @ SuperBiiz)
Total: $537.56
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2016-07-28 20:44 EDT-0400
EDIT: I've removed best answer as I don't feel it answers your question well due to vagueness regarding requirements and performance.
"every solid cpu it will run just as fast as your 6600k with a lot of tabs open Skype and a movie on the background."

Yes the i3-6100 is perfect for a non-gaming build. I've been outfitting all the computers at my job with i3s (previous gen ones no less). She doesn't need 16 Gb of RAM for that use case either, 8 or even 4 is enough.

If you want to keep it on the cheap, use this.
PCPartPicker part list / Price breakdown by merchant

CPU: Intel Core i3-6100 3.7GHz Dual-Core Processor ($110.99 @ SuperBiiz)
Motherboard: Gigabyte GA-H110M-A Micro ATX LGA1151 Motherboard ($49.99 @ Amazon)
Memory: G.Skill Ripjaws V Series 8GB (1 x 8GB) DDR4-2400 Memory ($33.99 @ Newegg)
Storage: Western Digital Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive ($47.49 @ OutletPC)
Case: HEC Voyager ATX Mid Tower Case ($22.98 @ Newegg)
Power Supply: Antec EarthWatts Green 380W 80+ Bronze Certified ATX Power Supply ($38.99 @ Newegg)
Total: $304.43
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2016-08-26 09:49 EDT-0400

If she wants to handle those web pages with speed why not try a Xeon?
PCPartPicker part list / Price breakdown by merchant

CPU: Intel Xeon E3-1231 V3 3.4GHz Quad-Core Processor ($252.99 @ SuperBiiz)
Motherboard: Gigabyte GA-B85M-DS3H-A Micro ATX LGA1150 Motherboard ($59.88 @ OutletPC)
Memory: G.Skill Ripjaws X Series 8GB (2 x 4GB) DDR3-1600 Memory ($37.88 @ OutletPC)
Storage: OCZ TRION 150 240GB 2.5" Solid State Drive ($59.99 @ Newegg)
Storage: Western Digital Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive ($47.49 @ OutletPC)
Case: Corsair 200R ATX Mid Tower Case ($54.99 @ Newegg)
Power Supply: EVGA 500W 80+ Bronze Certified ATX Power Supply ($43.88 @ OutletPC)
Total: $557.10
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2016-08-26 09:46 EDT-0400

Xeons take ages to boot, feature hyperthreading and are way overkill for OP's uses.
PSU is poor quality, and case is poorly priced.

I don't know if OP is still on this thread, but here is my build again for reference.
Only $300.
PCPartPicker part list / Price breakdown by merchant

CPU: Intel Core i3-6100 3.7GHz Dual-Core Processor ($110.99 @ SuperBiiz)
Motherboard: Gigabyte GA-H110M-A Micro ATX LGA1151 Motherboard ($49.99 @ Amazon)
Memory: G.Skill Ripjaws V Series 8GB (1 x 8GB) DDR4-2400 Memory ($33.99 @ Newegg)
Storage: Western Digital Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive ($47.49 @ OutletPC)
Case: HEC Voyager ATX Mid Tower Case ($22.98 @ Newegg)
Power Supply: Antec EarthWatts Green 380W 80+ Bronze Certified ATX Power Supply ($38.99 @ Newegg)
Total: $304.43
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2016-08-26 09:50 EDT-0400

What are you talking about xeons take forever to boot? Do you even own one? I have a Xeon PC at my job and it boots just as fast as my PC with an ssd. Both have an ssd. And that PSU is fine. Especially at this price point.

I HAVE owned a Xeon.
At your job it is likely running off a hub, and the system is already booted when you get in there, with you just using a terminal which will boot normally.
Here is an example: https://www.youtube.com/watch?v=kxYGM-MlngU

Go for 2x4GB on the memory. This will enable you to use dual-channel mode and will give it a little extra zip.

Wow, so many oddball things here. First of all, xeons don't have some weird issue that takes them forever to boot. Secondly, for basic email, web browsing etc, an i3 is plenty and an i5 is overkill. Ram is a key component for having multiple browser tabs open and depending what other software she uses, a 120-240gb ssd would likely be plenty. If she wanted to store photos an additional hdd could be added later for cheap and without reconfiguring windows.

While it's pretty common anymore to make use of dual channel and usually doesn't cost any more money for 2x4gb sticks vs 1x8gb stick, running ram in dual or even quad channel memory (x99) vs single channel provides nearly squat in real world performance. The extra 'zip' is in synthetic benchmarks, not real world use or real world applications.

Even if this were a gaming system the i3 6100 holds its own against the i5 pretty well in most titles.

Just some info pages to try and clear up some of the highly inaccurate myths floating around here.

On xeons taking longer to boot, read the whole article that discusses the additional boot time of a dual xeon workstation. Please realize that a dual xeon workstation is not a single xeon 1231v3 on the lga1151 desktop platform.

"Well, it all comes down to the amount of hardware that the Xeon build has to initialize. It has two processors, lots more memory, multiple network adapters and other I/O interfaces, and a dedicated RAID controller card. Just turning on and checking all that hardware takes time, and then once it gets to Windows itself there are also more drivers to load up before reaching the desktop."

https://www.pugetsystems.com/blog/2016/01/26/Boot-Time-Comparison-761/

On single vs dual channel memory.
http://www.tomshardware.com/reviews/PARALLEL-PROCESSING,1705-15.html

"dual-channel just isn't necessary for the vast majority of the consumer market." and "Gamers, mainstream users, and office users shouldn't care."
http://www.gamersnexus.net/guides/1349-ram-how-dual-channel-works-vs-single-channel/Page-3

On dual vs quad memory.
http://www.pcworld.com/article/2982965/components/quad-channel-ram-vs-dual-channel-ram-the-shocking-truth-about-their-performance.html

An i3, 8gb of ddr4 2400 and an ssd will be plenty for web browsing. Much of the 'net surfing' speed is going to be based on the person's internet connection.

In terms of hardware, I've got an i5 4690k, 8gb of ram, 3 browsers and over 90 (yes I counted) tabs open between 2 instances of chrome and 1 of another browser. I've got task manager open, 2 flash based games in the background on a couple tabs (which use a fair amount of memory compared to standard web pages), realtemp and a couple other small applications open. Cpu usage? 24%. Ram usage? 6.7gb.

When I close out the two tabs with the flash games open, cpu usage drops to 7% and ram usage drops to 5.48gb and I still have 90 tabs open. i5's and xeons (basically i5 with ht) are overkill for basic pc use.

I already knew that, and I have a feeling everyone else in this thread already knew that too. Given that it doesn't cost more to run dual-channel, why *not* do it? Even if the gain in system performance is less than 5%, it's a "free" 5% (or 2%, or whatever). This is an enthusiast site, and people take pride in doing things the best possible way, even if the actual benefit is almost purely theoretical.

I absolutely agree, if there's no price difference dual channel is fine. However it really doesn't matter and there won't be any real world difference. If there's a combo deal someone is considering or a sale involving a single 8gb stick it would be a shame for someone to pass it up feeling they would be losing performance they're not.

It has nothing to do with pride, if anything there's pride in accurate information. It's long been a perpetuated myth that dual channel (or quad) is 'worth it' because of some sort of performance gains. Aside from a very niche segment of users (and they already know who they are), additional memory channels offer in essence nothing over single channel.

I can't assume what others know or don't know in any thread, in this thread people were suggesting that a xeon was somehow something to avoid because of its painfully slow boot time. Omitting the fact that it was completely apples and oranges comparing a single cpu to multi cpu and heavily networked platform. In addition to the fact that quad cores and quad + ht are completely overkill for browsing the web.

Only trying to save the op from rushing to put together a quad xeon workstation with raid 0 and 32gb of ram so their mom can read email and check pinterest.

I hear you. I don't think I've ever seen the words "mom" and "Xeon" in the same sentence before. You definitely had your work cut out for you this time

This is my take on a pure web surfing / email checking / letter writing PC. This is literally all you need to have a computer that feels really fast when it's doing really easy things.

Component Selection Base Promo Shipping Tax Price Where
Intel Pentium G4400 3.3GHz $56.99 SuperBiiz
Asus B150M-K D3 Micro ATX LGA1151 Motherboard $49.99 + $5.39 $55.38 Newegg
Crucial 8GB (2 x 4GB) 1.35V DDR3-1600 Memory $35.99 + FREE $35.99 Newegg
Samsung 850 EVO-Series 250GB 2.5" Solid State Drive $89.39 FREE $89.39 Newegg
Western Digital Caviar Blue 1TB 3.5" 7200RPM $47.49 FREE $47.49 OutletPC
Cooler Master N200 MicroATX Mid Tower Case $42.99 FREE $42.99 NCIX US
EVGA 430W 80+ Certified ATX Power Supply $29.99 -$15.00 + $5.99 $20.98 Newegg
Asus DRW-24B1ST/BLK/B/AS DVD/CD Writer $16.88 $16.88 OutletPC
Microsoft Windows 10 Home OEM 64-bit $98.88 -$10.00 $88.88 OutletPC

TOTAL $454.97

Dual channel won't give you a great performance increase, 1x8GB is better for upgradability.
Case is overpriced, CPU is underpowered, SSD is overkill, PSU is poor quality.

Yeah, I face-palmed right after I posted that when I saw the case - I think I picked that one accidentally

But I stand by my position that a Pentium with 2C/2T and an SSD will give a subjectively better experience. Take this from someone who has G3258 machine to his left and a 5820K to his right. In Chrome, I cannot tell the difference between the Pentium and i7 at all - they're both lightning fast no matter how many tabs are open.

The SSD WILL make a difference. His mother wants a computer that feels responsive like his. Without an SSD, it will feel the way computers did before SSDs were cheap and ubiquitous - slow!

PSU is fine for this application. Its the one I have in my G3258 system, and I have no complaints at all about it. The machine is not even going to pull 200 watts.

C'mon, you can't possibly think hyperthreading is worth the money, but an SSD isn't.

During video playback the pentium can be stuttery (based off my experience with a haswell pentium in a relative's build), so the i3 is a better choice for a little more money. Given the increasing amount of power some basic applications use,(Google Earth for example) the i3 offers a much better experience.
Here is my build reposted with Windows included.
PCPartPicker part list / Price breakdown by merchant

CPU: Intel Core i3-6100 3.7GHz Dual-Core Processor ($110.99 @ SuperBiiz)
Motherboard: Gigabyte GA-H110M-A Micro ATX LGA1151 Motherboard ($49.99 @ Amazon)
Memory: G.Skill Ripjaws V Series 8GB (1 x 8GB) DDR4-2400 Memory ($33.99 @ Newegg)
Storage: Western Digital Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive ($47.49 @ OutletPC)
Case: HEC Voyager ATX Mid Tower Case ($22.98 @ Newegg)
Power Supply: Antec EarthWatts Green 380W 80+ Bronze Certified ATX Power Supply ($38.99 @ Newegg)
Operating System: Microsoft Windows 10 Home OEM 64-bit ($88.88 @ OutletPC)
Total: $393.31
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2016-08-27 04:07 EDT-0400

Well, I believe you, but I use my Pentium machine mostly as video player, day-in and day-out (I don't have or want Cable TV) and it streams 1080P video without a hiccup for me. Mine is a Haswell at 4.2GHz, but I'm pretty sure a Skylake at 3.3 or 3.5 wouldn't be far off. I haven't seen a computer hiccup during video playback since I got my first Core2Duo machine.

Your build looks good to me. I'm not going to quibble about our differences in memory or PSU selection, since I don't think they're significant. Like I said before, I still suggest a small SSD for a boot drive. I love SSD's, I can't help that. They're so fast, and they've gotten so cheap. They give the kind of performance boost that ordinary users can feel and appreciate right away. I even have a 250GB EVO in the 1C/2T Atom Z450 netbook that I'm typing this on, and it makes this little turd tolerable for web browsing in bed. If the OP's budget allows for the i3 AND SSD, that would be one quick machine for mom.

Yeah I agree.
The only concern I have is if emails etc. would be stored locally, in which case over time she'd build up local files and fill up the SSD as some older folk tend to do in my experience.
Storing media like family video etc. might she something she'd do, so i'd go with a 1TB HDD to be safe, although a combo is optimal for obvious reasons.
I'd say if you can squeeze it into your budget OP, you should get this:
PCPartPicker part list / Price breakdown by merchant

CPU: Intel Core i3-6100 3.7GHz Dual-Core Processor ($110.99 @ SuperBiiz)
Motherboard: Gigabyte GA-H110M-A Micro ATX LGA1151 Motherboard ($49.99 @ Amazon)
Memory: G.Skill Ripjaws V Series 8GB (1 x 8GB) DDR4-2400 Memory ($33.99 @ Newegg)
Storage: A-Data Premier SP550 120GB 2.5" Solid State Drive ($37.99 @ Amazon)
Storage: Western Digital Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive ($47.49 @ OutletPC)
Power Supply: Antec EarthWatts Green 380W 80+ Bronze Certified ATX Power Supply ($38.99 @ Newegg)
Operating System: Microsoft Windows 10 Home OEM 64-bit ($88.88 @ OutletPC)
Total: $408.32
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2016-08-27 05:27 EDT-0400

That build looks just right to me. I definitely agree about retaining the mechanical hard drive. Less-savvy users tend to let disk space get away from them for the reasons you stated. Not only that, but an SSD should never be filled past 90% anyway.

A Pentium G4400 is actually overkill for just casual use...

If you got stutter on the Pentium during video playback, it was a codec issue, format issue, or a I/O issue.

I'm having none of the issues described above using a stock A8-5500. The G32xx/G4400 is about 40% faster than mine, despite having 2 cores less, so I find this comment extremely hard to believe.

The very minimum for "casual" desktop use is the N2840+, it did everything I wanted it to paired with EMMC.

I believe these types of misinformation comes from people with experience with slower drives. For instance, a very old laptop with a very old CPU may seem sluggish to a lot of people, up until they upgrade to an SSD. So I mean cmon, a Pentium would be fine.

It's a tale as old as time. I don't think this applies to anyone in this thread, but a typical user (read: ignorant) complains that their CPU is too slow, or even thinks that they need more RAM, when the problem is almost always a tired old hard drive, highly fragmented, clogged with garbage, and probably riddled with malware. It's misconceptions like this that practically drive the consumer side of this industry. With the drastic slowing of increasing CPU power in the past decade, this is more true today than it ever was. 90% of the general public who think they need a new computer, do not. They just need a new GPU for their games (if any) and an SSD to speed up everything else. They also need to learn how to not bog their machines down with garbage, but that's probably asking too much. I would be out of a job