i would rather use this one...
HowStuffWorks "How to Build a Computer"if i was a beginner.
the best way of learning(in my oppinion) is to deasemble an old PC or the one you are gonne upgrade. then u get a clue of whats what, and a second thing u should be aware of... is the pins that go to the powerswitsch and lightning... those are important to get right, so you should read the mainboard manual to se where they are going.
i know how to put it together in under 4 min

(if i dont get problems like the GPU fan is to big XD