This should be your first stop.
Core2 Overclocking Guide (generic guide based on an Asus motherboard)http://www.tomshardware.co.uk/forum/259899-11-core-overclocking-guide
Next stop should be a guide for your particular motherboard. Google is your friend.
Don't expect a lot. Your CPU has a relatively high (333 MHz) FSB and a low internal multiplier. I would be surprised if you can get more than a stable 2.8 GHz out of it.