This video, created by the FreeNAS Team, shows how to configure FreeNAS for backups on Windows, Mac OSX, and PC-BSD.
FreeNAS 8.0.2 has been released, fixing some problems with the email subsystem: Announcing FreeNAS 8.0.2-RELEASE
FreeNAS video (backups in depth), and FreeNAS 8.0.2 available