According to the following, backup everything on the disk and backup the database:
http://www.activecollab.com/pages/20...-instructions/
So, what kind of database? Well, active collab is based on Apache, PHP and mySQL:
http://www.activecollab.com/support/...=kb.page&id=19
http://lifehacker.com/software/proje...lab-204274.php
So, the basic thing you need to figure out is how to backup mySQL. There is a bunch of stuff on the mysql.org web site:
google "backing up mysql site:mysql.org" or "backup mysql site:mysql.org"
And, if you have a bunch of stuff you want to backup and automate on a regular basis, and don't want to be bothered by writing your own scripts, you could try:
http://www.zmanda.com/backup-mysql.html
That (ZRM or Zmanda Recovery Manager for mySQL) can actually be integrated into any general backup program, e.g. Amanda or whatever else you are already using or decide to use.