I've been working on my very first PC build over the last three evenings. Tonight I plugged it in, crossed my fingers and turned it on... and booted into the BIOS config! Woohoo! I'm now past my worst fears of crushed CPU socket pins and the like. (And considering what I spent on all this, that was no small fear.) Tomorrow, I'll get the drives in and try to tidy up the cables, but for now I'm happy.
Now, I really do need to think of a good name for it.