Hi computerguy101, I will give you a couple of thing to think about. One is that most things are built into linux. That is lets say that you want to run a webserver, Apache is already built into the distro. Also, you don't have to go and buy a office program that is built in. It is OpenOffice.org. For the most part linux uses the resources of the computer better than windows. That is to say that there aren't as many programs running in the background, and the ones that are don't require a lot of ram.
As 01001010, has said it runs on older machines, so you don't have to have C2D, or C2Q. I am running fedora on an old hp with an AMD 3200+, 80GB hdd, and 750mb or ram.
Any other questions feel free to ask and we can do our best to answer them.
Cheers!