There's the ASUS overclocking thread in the Motherboard/Intel section that may be of use. Of course, if you are using something other than ASUS, you may have to do more digging as far as options goes within the BIOS and their respective names.
Basically, overclocking is based upon the turbo bins and multipliers rather than upping the general system speed (FSB). There's a ton of information out there.. not only on here but on various other sites as well.