I'm looking to build my own computer, but I'm not sure where to start.

[johndoeistaken]

I'm looking to build my own computer, but I'm not sure where to start. I have no problems putting it together, but making sure parts are compatible or what I need is the issue. I had purchased an Alienware X51, but both the original and replacement didn't want to boot. So I sent them back. I'm looking for something on the higher end. I7 quad(or more), 16(supports 32) Ram. As far as the motherboard, cooling, or exactly how much power I need, I'm at a loss. I've never built my own before.

 

[johndoeistaken]

I apologize for not having searched this before posting. I can't quite figure out how to delete this post.