Spent over two hours building the computer. Mini-ITX is small and hard to work with. I couldn't get my CD drive to fit, so I currently don't have a computer with a CD drive.
Couldn't get the computer to boot. Not sure if that's because of something it doesn't like about my primary hard drive, or because it can only boot from SATA. My primary hard drive is IDE, with an IDE-to-SATA converter plugged into it. Though I also threw it into an enclosure and tried to use it over USB. Both times the BIOS recognized it and seemed to be happy enough to try booting from it, but both times it threw an error. (And I'm sure the drive is fine; I can read it fine on another computer via the enclosure.) Maybe the error means I have a bad motherboard? Man, I really don't want to do this all over again.
EDIT: In researching the problem, I have found the strangest page on the internet. Also, we seem to be booting now. For some definition of "booting"; at least we're past the bios.