New computer purchase

[metguru]

I'm thinking about getting a new computer, but until now, i've gotten prebuilt computers. I'm thinking about building a cluster out of a few computers, and am hoping to get more out of my money by building my own, and having some fun too . I have links to all the pages of the hardware that is in the area of what I'm looking for, but since I don't know a lot about hardware(all i've ever done is added RAM to my dell, ), I was hoping you guys could help me find if everything is compatible and all.

[edit] Just so you guys know, it came out to be almost exactly $500 USD, including shipping.

I appreciate any help that you guys are willing to give!