How to ground myself while building my computer

Wristband connected to your case is really the safest way, i wouldn't take risks if i were you

Added as None of the above comments were posted when I starte writing this.
- It hard to make a wrist strap. They have a 1 megohm internal resistor to bleed a charg off slowly and as a safety factor. Also the clip from the wire to the band is designed to breakaway if by remote chance you deside to touch a high voltage point - SHOULD NOT be any when uilding/assemblin your PS.
- Yes you should use the three prong AC. The third prong is Ground.
End Added.

First off:
1) Depending where you live, we are entering the summer with High relative humidity (RH). High RH reduces the ability to develop a charge. Winter time is the worst. RH at 30 % is bad, but 20% is 10 times worse.
2) You do NOT even know you have a charge if below 500V to 1KV. You can have a 100->200V charge and NEVER know it – anyone say a CPU and Ram operate at < 1.5 V, Every component in a computer is =< 13V.
3) Rugs, wooden floors, Your idea of rubber slippers (really bad idea) – The ability to take on a charge is dependent on where the two dissimilar materials are located in a table. For example in the winter (RH =<30%) and sitting in a wooden chair the air blowing across your clothing can generate a charge very quickly. Reduced considerably BUT NOT eliminated with RH =>50%.
4) You have to touch the pins to damage a component (ie the Pins on the Ram, or the pins on the GPU) – FALSE. Explained in in 2nd link. If you are charged up say to 200V and you bring your pinky very close (NOT touching) you can still damage a component.
5) It is estimated that about 30% of DOA electronics is due to ESD damage. This does NOT include Walking wounded components that fail 3 Months to a year later, Nor does it include systems that work, just have reduced performance.

Defined:
http://en.wikipedia.org/wiki/Electrostatic_discharge
No need to read all, skip down to ESD failures, especially Walking wounded
http://www.ti.com/lit/an/ssya010/ssya010.pdf
Above is just two links out of the many out there.

My Recommendation:
A) Place Case on table
B) Install PSU, Verify PSU rocker switch is OFF, Plug PSU in (I use a Surge protected power strip) and
C) Connect Wrist strap to an UNPAINTED spot on the case.
PS wearing a $10->$15 wrist strap does NOT make a Geek out of you – Just means your smarter than the average Bear (Yogi something)
For system build-up, NO I do NOT use an ionizer, do use an ESD mat to sit components on – But that is because I have a freebie one. And Yes I’m ESD certified – Required recert every two years.

Bare feet is fine as long as your on a static dissapative surface - LOL.
RH 50% and higher, You are probably OK as long as you touch a "Grounded" surface - NOT a painted surface periodically and do NOT touch any of the conductive pins.

Personally I do wear a wrist strap even in the summer when (A) assembling a new build, and (B) installing a GPU, CPU, or Ram.

I'm reminded of a post some time ago where a individual "bricked" his HDD just setting in a a Glass shelf.

Bottom line - "Should be OK, and It's your call.

Added
On your Home outlet and Is it grounded. Most safety codes require AC outlets to be grounded for the Vast majority of civilized nations. AC wireing Consist of HOT, Nuetral and ground. Nuetral and Ground are tied together at some point. With two wire outlets you have a Hot and a nuetral - While there is a standard on which should be which it s sometimes violated, reversed.

This is the reason that 3-prong outlets became the standard Some 50 Years ago - Lost too many wives that touched the fridge with one hand and either the toaster or water tap. With two wire, and if the hot/nuetral were reversed the Outside metal was at 100 VAC

.. "I remember unboxing my video card an touching the ends of the card, I wonder if it got damaged or what." - PROBABLY NOT.

.. Plug into UPS, With UPS powered off and connected to wall IS FINE!!. That would be the same as PSU pluging directly in wall.

.. With Your HIGH RH, You should have no problem with periodically touching the case while assembling it (Yes Wrist strap would be prefered), just do not touch any of the contact pins.

you should NOT have the computer power supply plugged into the wall while assembling the parts of the computer - that is to be connected when all parts are installed on the motherboard, the case is secure, and you're ready to boot up for the first time

again, don't be afraid - just take your time... here's the steps:
- install the cpu on the motherboard (while it's outside the case)
- then install the heatsink on the cpu
- then install the motherboard in the case with the correct stand-off brass pieces
- then install memory
- then install and connect all drives and power supply to everything

once that's done, plug in the computer and monitor and boot up - once windows is installed and you've done all the windows updates, install your gpu with the latest drivers from either nvidia or ati

Dingo,"you should NOT have the computer power supply plugged into the wall"
Not correct:
1) As I indicated With PSU installed and rocker switch For PSU in the OFF position.
2) If unplugged then NO ground is supplied to case. If case is NOT grounded and you have a charge the ONLY thing you do is equalize the charge between you and the case.

Option if you want to leave PSU pwr cord disconnected is to connect a ground wire from case to Gndat wall outlet.

let's be real RetiredChief - i'm not discounting the principles you mention - but it's common sense that noone builds a computer with the power supply plugged into anything until they're ready to power it up

and the OP already stated he has no 3rd pin (ground) in his wall sockets

1) He asked the question - not sure if he said he did not have. Then qualified by saying that he is plugging into a UPS, Which I also recommend that he turn OFF.
.. The UPS will TELL him right quickly if he has hot and nuetral reversed and Nuetral is tied to ground at some point.

2) I think I am being real, and yes I DO my build with either the PSU installed and PLUGGED in (And there are others that have possed here at Tom's that also recommend PSU plugged in). I normally use a surge power strip with that also turned OFF. I use one of 3 grounds for my wrist strap.
... Unpainted case
... Plug my wrist strap into the Round Ground plug of one of the outlets on the power strip
.. Or, connect to the ground point on my ESD mat, which is plugged into the round ground outlet on the surge protector strip (or directly into the Wall out let ground) - NOTE I've verified my house wiring.

PS Otherwise, Totally agree with the steps you outlined
Quote
- install the cpu on the motherboard (while it's outside the case)
- then install the heatsink on the cpu
- then install the motherboard in the case with the correct stand-off brass pieces
- then install memory
- then install and connect all drives and power supply to everything
End quote.

Although I do normally install my Ram before placing MB in case.
Surprising there are a few that forget the standoffs and watch the MB and PSU yell and die.

ENJOY!!

sounds about right for your location. if you want to double-check, remove the heat sink on the cpu and re-apply the TIM, making sure there's no extra on any side that runs out - a "pea" size in the center works well.

Concur with Dingo on Thermal paste. Too much is just as bad as too little. What I do is with that "Pea" size amount (I use AS5) then with a latex glove I try to evenly spread it.

On temps. For a room temp of 22C (72F) and at IDLE low to mid 30's are great with the Stock HSF, 51 is NOT. I'm quessing your room temp is higher, do to location, At 27 C (81F) I would expect low to mid 40's.

That said:
1) It is NOT the idle temps that are important, it is the temps when loaded.
2) The stock INTEL HSF is at the Bottom of the totom pole and if your running a room temp of 80+F (=>27C), then I recommend replacing the Intel HSF with a 3rd party cooler (for the price the Hyper 212+ is a good choice). SIDE Comment, it is common that with the Intel HSF, one of the post is not locked into place properly.

3). Looking at the spread of temps (individual cores) if 35C->51 C.
A) One core may have a higher workload at idle, but normally that would be like 35 for 3 cores and 45 for one core.
B) recommend testing where all 4 cores have the same workload. What I do is run Prime 95 - ONLY NEED to run for a short Time ie about 10 Mins to check temperatures, To check stability, 2 -> 4 hours, (But I think running more than 10->15 minute will put you above 85C) Anyway run it for about 10 Min monitoring your temps. At the ened of 10 Min if you have one core >10C higher than the other cores then that indicates the HSF is NOT setted correctly, or you do not have a even coating of the Thermal paste.

-- Do not get real concerned if you start hitting 80C (max temp for SB/IB CPUs is 95C at which time they will throtlle back to protect themselves). Prime 95 works your CPU much harder than normal and gaming.

On HSF, Pick the most demanding application that you will normally run and run for a couple of hours while monitoring temps, if under 75C OK, if higher then replace HSF. Personally I use 65 C as My limit, but that's me.

You did not indicate what CPU you are using (or I missed it)
So Based on a Ivybridge i5 or i3-3xxx
You can leave it run a little longer, what you looking for is that the 4 cores are close, Not more than a 10C spread) to indicate even HSF pressure and even spread of HS Compound.
As I indicated the IB is OK at 80/85 C for testing as they do NOT even throttle untill 95->100 C at which time they will PROTECT themselves by cutting back.