My computer's harddrive crashed recently. I've decided that I would like to try to build a desktop from components I've canabalized from my old (but relatively new) PC and from new components.

I have a rather nice guide that I'm reading, but I was just wondering: are there are steps in the process that a noob would be prone to fuck up, or is there anything I need to keep in mind that may not be so obvious? I'm not extraordinarily tech-savy, but I'm at least more proficient than average, and at least on the face of it, building a desktop doesn't seem terribly daunting...