Our generic guide (same as above link):
This should be your first stop.
HOWTO: Overclock C2Q (Quads) and C2D (Duals) - Guide v1.6.1http://www.tomshardware.com/forum/240001-29-howto-overclock-quads-duals-guide
Next stop should be a guide for your particular motherboard. Google is your friend.
Overclocking 680i/780i chipsets:http://www.tomshardware.com/forum/263006-29-overclock-q6600-680i#t1884029
Keep in mind that, in the link, we are talking about DDR2 RAM, not DDR3 RAM like you have. Your max memory voltage drops to 1.65 volts. And RAM clock frequencies double. For an FSB:RAM ratio of 1:1, your FSB clock will equal your RAM clock.