Making a Computer

I'm looking to build my own pc, and I need to know a few things, since I'm not exactly a profesional. In fact I'm pretty new to starting from scratch.

I know the basic needs for a computer
CPU
Motherboard
Video Card
Sound Card
Power Supply
Etc.

Anyone willing to give me important advice for builing my own PC?

Also recomendations for new technology to make sure to include would be nice.
(IE: don't buy a Motherboard w/o PCI Express, or try for SATA cables.)

Thanks in advance.

I have so far these -> Asus A8N-SLI Deluxe - AMD 3200+ - Antec TruePower 2.0(430 watts)

Need these -> 2x512MB PC3200 RAM sticks - Nvidia GeForce 6600 - Antec Case (one like my old PlusView1000AMG)

AM I DOING IT RITE?