In this article I am going to show you how to quickly set up your computer for simple, hassle-free, and transparent backups using only rsync and cron (or Anacron). The premise is simple: every night your computer will make an automatic mirror of all the files you wish to backup, and at chosen intervals these mirrors will be archived and kept for a specified period of time.

Everytime I read something like this I promise myself that I will implement it, but always fail to. For right now I just place my faith in the computer gods and the 250GB Maxtor Firewire drive that I use.

In any case this is a really good article that even covers setting up a backup policy before you get started.