OC'ing a desktop computer :D?

I have a q6600 (quad core 2.4Ghz stock) processor and a EVGA 680i mobo. I can access the boot menu and up the FSB easily. however, if i up it to 333 (i think that's what it is to get 3.0Ghz) do i need to up the voltage too? i can link the FSB to the RAM, so they will step up together. also, is there a reason to increase the FSB a little at a time? is it just for stress testing it or is it to increase the voltage a little at a time because it puts less stress on it? or something like that. idk, can anyone help me?