i already know the basics i guess
1) Is bios posting? If no, then
- do all fans and devices have power going to them? If no, then its the power supply. If yes, then its the motherboard
If bios does post, then its fairly simple determining whether or not its the processor or the hard drive from that point on
If graphical elements are distorted, then its the video card

I mean its not difficult but I know there are problems out there that I haven't encountered yet, and I wouldn't know what to do when they finally come along