Isn't the current release f11, making f9 unsupported?
it's easiest to encrypt root at install
http://linux.ioerror.us/2008/02/encr...s-in-fedora-9/
but post-install is possible
http://forums.fedoraforum.org/showthread.php?t=214506
generally
http://tldp.org/HOWTO/Encrypted-Root-Filesystem-HOWTO/
Much depends on the details of the partitioning - are you using LVM for eg? One of the cool methods is to put /boot on a keydrive, configure the machine to boot from the keydrive, then you can do true whole disk encryption. Keep the usb key on your keyring.
However, I've found encryption to this degree more trouble than it's worth.
