For the uninitiated, the use of disk druid is non-obvious. The documentation on
the partitioning process during installation is very terse. It would make sense
to repurpose the far superior documentation on this subject from Fedora:

http://docs.fedoraproject.org/install-guide/fc6/en/ch-disk-partitioning.
html#sn-partitioning-general

That page, and the subsequent page on Disk Druid specifically, is very clear and
more than sufficient to get a new user through the process.