First Build not sure

I need some advice on building my own pc. First off, this pc is basically going to be a
backup pc used for surfing, a great deal of word processing, music, movies and tv. I seldom play any type of games. I’m planning on using a plextor dvd burner (px 760A) that I took out of another pc, I also have a 300 Gb hard drive, and a cd burner, a 400W cool max psu from again another pc, so those are items I don’t need. I’d like to stay in a budget of under six hundred, if that’s possible, as this unit is basically a backup, however I want to be able to update/expand it in the future.
I am looking at the following items, and would appreciate any and all input, as I’ve never built a pc.

Motherboard:
Asus A8N-SLI SE NVIDIA Socket 939 ATX Motherboard / Audio / PCI Express / SLI Ready / Gigabit LAN / S/PDIF / USB 2.0 / Serial ATA / RAID
http://www.tigerdirect.com/applica [...] .asp?EdpNo =2949323&CatId=13

Processor:
AMD Athlon 64 X2 4200+ 2.20GHz / 1MB Cache / 1000MHz FSB / Socket AM2 / Dual-Core (Windsor) / Processor with Fan
http://www.tigerdirect.com/applica [...] asp?EdpNo= 2207247&CatId=2328

Memory:
Crucial Ballistix Tracer Dual Channel 2048MB PC4000 DDR 500MHz Memory (2 x 1024MB)
http://www.tigerdirect.com/applica [...] ils.asp?Ed pNo=1558747&sku=C19-4086

Case:
Cooler Master Centurion 5 - Silver ATX Mid-Tower Case with Front USB, Firewire and Audio Ports
http://www.tigerdirect.com/applica [...] s.asp?EdpN o=1028568&Sku=C283-1002

Nope they aren't, you need to find AM2 socket motherboard .

If you aren't overclocking the stock cooler will do just fine.

Also your first link doesn't work

If you have any questions msg me if you want on aim or yahoo: Maximus9102