Ubuntu 8.04 Server and Backups

[Hurmoth]

I'm looking to backup one of my terabyte hard drives to another one ( /dev/sda to /dev/sdb - well specifically a directory on sda that will contact a lot of important data). I've thought about using Acronis to create an image whenever I want to back it up, but I'd personally rather have it automated.

I was wondering if anyone has any suggestions on software to use to back it up where I could automate an incremental backup. I know there's a way to do it in the system using cron, but not sure how to do it making it incremental.

[Farstrider]

The best and easiest back up solution and it's free! Go here and have a look!

[Hurmoth]

Need a little more help, considering I'm new to writing shell scripts.

#!/bin/bash
sudo rsync -av --progress --delete --log-file=/mnt/bak/$(date +%m%d%Y)_rsync.log /home /mnt/bak

How do I get it to do incremental updates and is there a way to get it to delete incremental updates after say a week or so automatically so I'm not having to go in and delete old backups that aren't needed anymore?