Dont think i have the confidence to build a PC from scratch!
The inside of a PC tower may seem like a complex tangle of cables and PCB boards, which it is, but as far as assembling individual components together is concerned it is really very straight forward stuff. All the components are increasingly made to be fool proof, so there is no chance of you putting anything in incorrectly or anything like that. If something doesn't fit somewhere, then it doesn't go there and if something does fit, then it probably does go there.