One of the great joys of using fans to cool your system is that, in a lot of circumstances, you really don’t have to do anything to create a decent cooling setup. If your system’s chassis is of the non-bargain-bin variety, odds are high that its manufacturer has already installed exactly what you need—namely, an intake fan in the front that pushes outside air over your hard drives and an exhaust fan that shoots hot air flying out of the rear of the chassis.
Graphics cards and computer processors pretty much always ship with powerful stock fans—you know, the ones that sound like a plane taking off when they roar into action. Those, combined with case fans, make up the Holy Trifecta of air cooling within a typical desktop PC.