Well dude 1st of all you should get a crystal orb for the GPU thats 1 and 2nd get ARtic Silver to put between the GPU and the orb 3rd use that also for the video cards ram and heat sinks when you get that out of the way then.
go to like overlockers.com or where ever and download the registry patch that enables you to adjust the clock settings in your windows its way more stable and works sooooo much better, then just go up a little at a time not all at once and youll find a stable point yo should do it slowly over 2 or 3 days to make sure what ever setting you have it on is STABLE STABLE.

i know cause iv done it on many cards and cpu i just love to overclock
good luck ill keep tabs if you still need more info/help.