^ +1
OC Genie is dreadful because it is so conservative on its voltage (WAY too high for 4.2ghz)
Use the guide linked by henydiah, mrface's overclocking guide is probably the best guide for newbies in overclocking.
It also helps that mrface is an active member of tomshardware and if you run in to any trouble you should pm him
One thing he does not mention is to changing your vcore but that's not that hard;
if you have questions let me know
Side note: P67A-GD65 is a very good mobo for overclocking and the UEIF interface does make it a little easier for first time overclockers.