you could try Amanda.  While I haven't personally used it, I have been told that it is a good free backup program.

Linux comes with dump / restore - the oldies but goodies.

Amanda is a mess to configure (badly documented, mostly) but worth the trouble if you have multiple machines and want to keep a library of various versions of various levels of backup.

If you have a single machine and just want to make a daily backup to a local tape drive, use dump.

I recommend Arkeia as backup software. I've been using it on many machines running Linux or Microsoft Windows.

Arkeia comes for free in a light version but doesn't cost much in full version.

It's easy to configure and very easy to run. Well documented.

amanda is only worth the trouble if you are backing up many servers over a network. It is very good at this I use it for over 2 years in production at a previous job.
If you're just backing up a single server amanda is not worth the trouble.

This question really depends on what you want backed up. If you just want user data, current webroots, etc... then well written scripts using tar is the best method. If you want a full system backup with incrementals durring the week you'll be best off with a commercial product as mentioned in the above post.

Also, The method and tools for unix backup has not changed much in the last 20 years. almost any documentation you find online will and apply.
good luck,
chrisj