I have decided to take the plunge and build my first gaming rig. What I have so far:
CPU- AMD Athlon 64 3700+ 1ghz FSB socket 939.
MOBO-MSI K8N NEO4-platinum socket 939.
Video-Sapphire 100600SR Radeon X800 pro (256mb/256bit).
RAM-Corsair XMS 1GB (2x 512mb)184 pin dual channel DDR400 (pc3200)
Hard Drive-Seagate Barracuda 7200.8 250GB serial ATA 150.
All parts to be purchased at NEWEGG.
These are the important parts. The optical drives I can probably figure out myself. I am not sure about power supply (is 480 watt enough?)I was thinking of the standard Athlon CPU fan and heat sink with 2 or 3 other case fans.I am not real picky about the case. So what do you guys think about the specs so far? and any answers to the questions i posed would be greatly appreciated, thanks in advance.
(oh, my goal was to build a NICE gaming rig, not necessarily a KILLER gaming rig.)

Seems to me you ARE building a killer gaming rig...or darn close to it...lol!

The stock HSF & a couple of case fans should be fine. Choose your case wisely. Better to buy a quality case w/o a PSU, then buy the PSU separately. Shipping costs for a case are pretty high, so you may do better if you shop locally.

A 480W PSU should be fine, provided it's decent quality one & it's the right type. Check the ATX power connector on the board...it's probably the 24-pin type, plus you'll want a PSU with SATA power connectors. I'm guessing you'll need a unit that conforms to the new ATX12V 2.0 standard

ASUS A7N8X-X
Athlon XP 1800+
8.5 x 200MHz
1024MB PC3200 2.5-3-3-7
Asus A9550GE/TD 128MB
WinME/WinXP Pro SP1

Ill agree with jam on the PSU, mae sure you get one with SATA connections. While there are adapters for it, they tend to be really poorly made and fall to bits, i haven't found one yet that can stand being pulled out even a few times

AMD Athlon64 3500+
1024MB 512x2 Dual Channel Corsair TwinX
Coolermaster Wavemaster
120GB Seagate SATA HDD
Gecube X800XT Platinum
Logitch 5.1 Surround
LG 16x Dual Layer DVD
Countle

Thanks Jam and Houston for the info, it was very helpful. My ceiling was about 1500 bucks and think I can make that. I guess the terminology NICE as oppossed to KILLER is all subjective. I was basing my rig against the guy who came into some bucks and was going to run twin 7800GTX cards in a SLI hook up (now thats KILLER)

Creative Sound Blaster Audigy 2 ZS Gamer Edition-69 at compusa after rebates or don't get it and save.
Don't forget windows/ and Arctic SIlver 5. OCZ ram might be better. Don't get Ati, get nvidia because they support SM 3.0. Make sure you get at least 18A on the +12V on the psu. The wattage is important, but the +12V is also very important.

ASPIRE ATXB4KLW-AL Antec 400W
ASUS A8N-SLI Deluxe
AMD 3700+ San Diego
Corsair 1GB 2x512
eVGA 6600GT
250GB Hard Drive
Sound Blaster Audigy
Windows XP HOME W/SP2

I agree with damasta, A lot of the new games that are being released are implamenting shader model v3.0, futher more, many of the current game producers are releasing SM v3.0 patches for their games, such as farcry and C.O.R.E.F.B.B. And might really wanna consider getting a Case from a local store, I was lucky enough to find a case on Newegg that only charged $5.00 for shipping. LooK for a good Brand named PSU @ 480watts (or above) with 20a (Or above) on the +12 rail, that should surffice.

CHIPSET---i865pe
CPU-------Prescott 2.8ghz @ 4004Mhz 286x14
FSB-------@ 1144Mhz
RAM-------512x2 in dual config @ 430mhz
GPU-------PNY 6800 16x1,5vp
OS--------WinXP SP2
HDD-------36gig WD Raptor

Arctic Silver 5 is unnecessary, but if you want to use it, be VERY careful and don't overapply it since micronized silver is an exceptional electric conductor.

Bw aware it voids any warranty you have with AMD.

I don't see much of a point in using it with Athlon 64's. They run pretty darn cool anyway.

"Barbara Streisand hasn't ruined the culture since Yentl."

I already have a Sound Blaster Audigy Z2 Gamer sound card in my old system. I was going to just use the integrated sound on my MOBO since it comes with 8 channel sound and I probably will not be able to tell the difference. Since you think SM 3.0 is significant, what NVIDIA card do you think is comparable to the Radeon X800 pro that I was going to get?

The Audigy 2 is a superior soundcard to your onboard soundcard, especially considering it supports more advanced EAX effects than what your onboard does. (onboard probably does EAX 2.0 at best) Your call if that's enough of a reason to put it in your new rig.

Nvidia 6800 would be comparable.

"Republicans in Congress are moving to ratify a constitutional amendment to ban flag burning, thus ending the Iraq insurgency."

Thanks Heropyscho, I will certainly put the sound card in my new rig, and I will look at the 6800 video card.