Ok so seems like we have some members that don't know how to build a pc, it's pretty much like legos, but since I'm horrible at explaining, here's a very detailed link from IGN, just ignore their choices for hardware since it's an old a rticle.
http://gear.ign.com/articles/579/579077p1.html
and another very useful link with more pics
http://www.waterwheel.com/Build_A_PC..._PC_Step_1.htm
Of course, we're all here to help each other, so any questions, no matter how small or silly it might be, just ask, and when the time comes, we can help as well via vent on doing it step by step if needed
Also keep in mind that there are many places in the net to buy parts, so always post the links of the parts you plan to buy so we all review them and point any incompatibilities or price debates.