Try here theres lots of info about overclocking click here I just want to confirm you know the risks. Essentialy when you overclock you are forcing the hardware to go beyond the design limitations and the main result of this is heat. Go too far and the processor blows leaving you with a very large paperweight.
Its up to you I'm not trying to tell you not to do it I just want to make sure you know the risks before you continue.
Personally I know a bit about it but not enough to give advice. Hopefully some of the others will chip in.