Not only is cooling important, but what components you are using is, as well. Yes, you can overclock with almost anything, but not everything will overclock well. There are general things to look for. For CPU's, it can be revision, stepping, or a certain model. Ram, it can be certain chips or PCB. Motherboards are usually either good overclockers, or poor ones, and overclocking is heavily dependent on the bios used, along with voltage options. For video cards, there isn't much you can do, but something most of the other components lack, are mods. Such as 256bit 9500pro's, some were moddable to open up the rest of the pipelines, which effectively turned it into a 9700pro! These mods are usually more rewarding than regular overclocking, but once the card is modded, you can overclock too! For the most up to date information on which components overclock the best, check the forums !
