You may not get it that high.
System specs? Motherboard and RAM make a big difference. So do case and CPU cooler.
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.