I own a money transfer company, which is considered to be a small firm. We have around 10-15 computers on our network. I am currently using a backup software called Safeguard.
It basically works unattended i.e you create the backup program once by determining all the data you want to backup then you schedule it according to how often you want the backup to occur. It also acts as an archiving and versioning system as a result of the database found in it, allowing you to retrieve all versions of your files immediately.
You can download a free version on this website:
http://www.epsam.com