I'm hoping to start my first build in the next couple of weeks. These are the components that I've decided on so far, but I thought it'd be a good idea to post and see if any of you more experienced builders can point out potential problems or offer any other advice. I'd appreciate any comments you have to offer.

This system will be used primarily for gaming, but I'll also need to use it for schoolwork and photoshop from time to time. No DV editing, rendering, etc. I plan to use Vista Ultimate 64 bit.

Case: CM Cosmos 1000

Motherboard: ASUS P5E Intel X38

Processor: C2D E8400 (assuming I can get my hands on one soon)
*I plan to do a moderate amount of overclocking on aftermarket air cooling, I've heard Wolfdale has a fair amount of FSB headroom w/ relatively little heat production.

Memory: 4Gb (2x2) GSkill DDR2 1000
*Don't want to pay DDR3 premium prices. Will this along with the X38 allow me to achieve a decent OC on the 8400?

Video: 2 x HD3870 in Crossfire
*I've heard that these scale better than SLI, resulting in near equal performance to the 8800GT in SLI. I also like being able to add a third (and more advanced) ATI card to my machine at a later date.

HD: WD AAKS 750GB + 150GB Raptor
*I'm going to put Windows on the 750 and games on the raptor.

Power Supply: PC P&C Quad 750W

CPU Cooler: Zalman 9700

Monitor: Samsung 226BW 22" 2ms 1680 x 1050

Can't wait to hear what you guys have to say. Don't pull any punches, I'm open to suggestions.

Take only one 750GB and take Raptor. Install Vista on 750GB and install the games on Raptor.

Thanks. So now I'll be using one Raptor and one 750GB, and I don't have to worry about RAID.

Raptors are a waste. Get a second Sata drive, you'll never notice the difference, and it's 1/5 the cost per gigabyte.

Also 750GB is HUGE, equivalent to more than 150 fully loaded DVDs. Get 2x 250's or 320's if you must, but look at how much space you are using now to determine how much space you should have. I have 500GB of storage, only 20% of which is used.

Is it a good idea to have two different size hard drives, one of which will hold windows, documents, videos, etc. and the other for games? If so, it sounds like size is more important than performance for the windows drive and vice versa for the games drive.

Anyone else use a setup like this?

Oh yeah, at least one drive will need to be 500+GB because I have ~90 uncompressed DVD files that will need to be stored on it from the beginning.

Put your OS on the smaller one, data on the other. Depending on your use, you could set up 3 drives - OS, data, video. Windoze can access all the drives at the same time, speeding up throughput significantly.

Thanks a lot for the help. Windows gets left alone on a small drive, and a big drive will hold all of the videos, powerpoints, etc. Now my only question is about the games. Will I see any significant improvement by giving them their own drive, or should I just let them install to the windows drive? Or install them to the big storage drive?

I wouldn't say that 750gb was HUGE nor surplus to requirements.
Taking into account of your DVD files, and the fact that the majority of new games will take up a chunk of space (Such as Crysis, CoD 4, FEAR, R6: Vegas, Halo 2 all 5gb or more while Kane & Lynch takes 7GB, Blacksite Area 51 takes up 11GB and for some reason my Gears of War reports 16GB! That can't be right?)
You don't want to be incorporating a new drive into your system in a couple of months, especially if you go the RAID route.

I've got two systems with different configs.
The first has three 500GB SATA drives, no RAID.
XP and Vista dual boot from one of those, one is for new downloads, and the other is an archive of movies and music I've decided to keep for good.

My second system has a 74Gb Raptor and a 500GB both SATA.
I tried this system in both configs (XP on raptor and games/downloads on the 500Gb, and vice versa) and to be honest, I noticed absolutely NO difference in performance, other than a couple of seconds off the boot time for Windows when it was installed on the Raptor drive.

Trust me, with the crossfire 3870s and the E8400 with 4GB of DDR2 1000, you won't have to worry about the performance of your games. They will fly!

You won't be able to tell the difference between setups in your games, I guarantee it. The FPS will be different, but nothing even close to you being able to notice by eye.

(BTW, I don't know if this will make a huge difference but all my 500GB are 32MB cache. I don't have any other SATA drives with less cache to compare performance. I don't think it will increase performance all that much)

Also, I've looked at the rest of your list and can't believe this is your first build! You've matched the different components extremely well. This is going to be a great system.
The case you've chosen is especially good for overclocking and multi GPU systems like yours.

As you said that you intend to do some moderate overclocking your DDR2 should do you well. If you really want to push the E8400 to it's limits you may want to consider DDR3 as this will put less strain on the motherboard and it's chipsets. But all in all you shouldn't have to worry about that.

The Zalman 9700 is an excellent cooler and I'm using it in both my setups. It's ideal if you aren't a total extremest and don't want to mess around with watercooling.

Not much to say about your PSU except that it is more than capable of running your system and then some. It has more connectors than you can shake a stick at, although it doesn't have a modular system so the cables can look quite messy in smaller cases. This won't be a problem with the Coolermaster Cosmos, and you'll probably appreciate the longer cable length.

Your choice of motherboard will provide you with everything you need to do your overclock, and performs amazingly well under tests. Not much else to say other than good luck with your build, you are going to have a lot of fun!

Thanks sumlock, I think that pretty much answers all of my questions. As soon as I can find an 8400 this'll be a done deal.