Need help with overclocking i7920

Hi i am actually new to overclocking and recently i have bought a i7920 2.66 with asus p6t v2 deluxe motherboard.Can any help me with it as how to over clock with stock cooler and how far can i go with an upgraded cooler??
Specs of my PC are as follows;
i7 920
Asus P6T V2 Deluxe Motherboard.
XFX GTX 295 Graphic Card.
Cossair XMS 4 GB Ram.
Segate 1.5TB Hard Disk.
COOLER MASTER CHASSIS CM STORM SNIPER BLACK EDITION.