Matthew,
Check out the Filesystem Hierarchy Standard
http://www.pathname.com/fhs/2.0/fhs-toc.html.
In general I have found 4 partitions ideal
Read-only usage, changes infrequently
(infrequent backups, optimizable layout, emergency backup
on insertable CD)
/, /usr, /etc, /opt, ...
Writable usage, directories change infrequently, file contents change
frequently
(rarely backed up, not worth recovering if lost)
/var, /tmp, ...
Writable usage, directories and file contents change frequently
(frequent backups)
/home, ...
Swap
Welcome,
Dr. Robert Meier