overclocking has been covered many many many times in this forum... do a thread search first and if you dont find the answers you want come back here
I would suggest you download the following PDF and take a look at this guide. Page 146 onwards covers overclocking, but the whole document is very good at explaining how to set your PC up correctly, as most people don't bother changing the standard settings from setup. You will gain a lot of performance increase just by spending the time going through the various systems and setting things up correctly and disabling those items that are not required. http://www.tweakguides.com/TGTC.html As for your particular board, it would be best to do a Google search on the exact model, using the phrase 'overclocking the asusxxxxp4' for example, matching the search to your details. Regardless of what CPU you have, the main area that will give you the ability to overclock is your motherboard, as that is where you will find all the parameters that can be changed in the BIOS, so without that info you are going nowhere.