OCing the gfx card will be no sweat... pretty simple stuff, MSI or nVid control panel settings are a simple as moving a slide back and forth.. Gotta keep an eye on fanspeed and temp, thou.
OCing ur CPU is a bit more, ermm, shall we say, involved, complicated, etc.. Have to deal with CPU multipliers, UBLCK settings, voltages, etc.
If you're even thinking of OCing, I'd recommned that you have an aftermarket cooler, that's almost a necessity, especially if you plan on doing stress testing. I have i7 930 2.8Ghz. Just overclocked it to 4.04Ghz, stable. Im a bit concerned with heat levels, idle is around 50-55C, even with a newly-installed Corsair H50 water cooled system. (although I hear now utilizing a push-pull setup with the H50 really improves performance/lowers temps. Good luck.