believe me, building PCs are a piece of cake...
as long as you do a bit of research, i.e. make sure you buy the right mainboard for the processor, the right memory for the mainboard, the rest of it you are pretty safe with.
auto detect ide devices in the bios, then fdisk the hd, format and install your (and the worlds) favourite OS.
you can really go wrong, because every bit fits in where its suppose to. (make sure you read the mainboard manual)
you'll probably find that it goes wrong, one or some of the parts are faulty.
infact the most time consuming part is installing windows!
i built my first PC in less than half an hour!!!