How do I overclock my system

[squeakmaster15]

I was wondering how I could overclock my computer. I know it can do a lot more than it does.

Specs:

AMD Athlon 64 3000 socket 939
DFI NF4 Lan Party mobo
2 Gb Corsair Ram 4*512
ATI Radeon x600
Western Digital 200GB HD
550 Watt PSU