Intel i7 920 & EVGA X58I OC Issues

I am in need of help! Mostly because I don't know what I am doing. It appears from many posts and online guides that Over-Clocking the i7 is very simple and stable. I am running into an issue where the machine will POST after making minor changes to the OC utility in BIOS. I have followed other guides to the "T", but without failure the machine will not boot. I am able to run very stable using default settings. I guess I really need a guide on understanding OC, what certain things mean and its functions, etc... I am not asking for someone to spend a lot of time on this, maybe just a few links that I can follow.

My Specs:

::Intel i7 920
::EVGA X58i 3XSLI
: CZ Platinum 6GB DDR3 1600
::EVGA 9800GTX+
::LG 22X DVD±R DVD Burner
::Seagate Barracuda 7200.11 32MB/3.0Gb/s
::LIAN LI PC-7B
::COOLER MASTER V8
::COOLER MASTER UCP RS700 80+
::Windows XP64bit