errr, take it you mean self build computer project....
firstly unless you have some very specficic hardware needs it is rarely worth building a computer yourself these days from a money point of view. You'll normally be better off buying a pre built machine that will meet your needs
I will assume that as you have asked about self builds you are looking to learn more about them, it which case it is not a bad way to start. there is a website here
http://www.pcmech.com/byopc/ that will help.
It is not hard at all to build your own PC, you normally only need about 10 parts to build a working system but in working out which of the parts is the best to buy you can learn a lot
Check the site and if your unsure about anything post back and sure someone on here will assist you.