overclock depends on the capabilites of these components:
CPU, mobo, ram, PSU and cooling.
if your new, the best thing to do it take it easy.
from the bios, just raise your fsb a bit (5mhz at most per increment)
then begin stress testing your cpu. I like prime95 myself (blended test)
you can keep doing this until your test fails or you can't boot into your O/S OR you can't get past the POST screen...etc etc...
then you have a bunch of options including voltage, lower your multiplier, ram timings..c... which I wouldnt touch without experience.
Its always best to learn by taking older, more importantly cheaper parts and experimenting.... this way you dont feel to bad when you accidently destroy something