Here's your parts list:

CPU: Athlon 64 3500+ OR 3800+ (do not get 3700+ or I will hunt your family down)
Motherboard: DFI Lanparty UT nF4 Ultra-D OR MSI K8N Neo4 Platinum
RAM: OCZ Premier 1 GB dual channel pack (you have no need for 2 GB of memory)
Graphics: nVidia 7600GT (any brand works)
Hard Drive: Seagate Barracuda 7200.9 200 GB S-ATA
DVD: LG GSA-H10A OR NEC ND-3550
Monitor: I can't make suggestions because it totally depends on which stores are near you
Keyboard: Whatever you want
Mouse: Logitech G5, hands down

Now, these are the most basic compotents. One major component that I left out is power supply. I'm going to include it in this section because it involves more writing than the other parts. It is absolutely crucial that you get a high-quality power supply. I suggest the Enermax Noisetaker 480W or Antec Truepower 480W. These are the absolute best units in the sub-$100 price range, and any other unit is a mistake. DO NOT GO CHEAP ON POWER SUPPLY!!

And last but not least, you sound like a noob so get someone that knows computers to help you build this computer. As much as I would like to guide you from start to finish, forums have limitations and a job like this requires hands-on work. Or you can take the tough road: self-teach yourself everything you need to know and build the computer by yourself. That's what I did...