There's a picture of a mounting setup here:
K-Ray's site has shots of the BIOS screens:
And you also may have to set "Large Disk Access Mode" to "DOS" to get some drives to work.
For mounting, remove the MB, put the drive underneath where it fits and wire it up. Some use tape to keep it in place, but I countersunk four screws (gotta love the dremel) to mount the drive from the bottom. I had the whole thing apart at the time, don't try it with anything in there of course.