Make sure you pick the correct HD to put it on.

At the bottom of the screen, when you are setting up the partitions, there is
also a place to pick the drive to place the boot tables, grub, on. (At least
this is the case for me. I have two HDs present and install on a HD that already
has Ubuntu installed. That may be different with your install.) Just a heads-up.
My two HDs are internal. One is almost only used as a backup.

Sounds like you are savvy enough to pull this off with no problems. For someone
that is not familiar with using Fdisk and Format on a HD installing Ubuntu could
be a real challenge.