I think that Amanda is one of the better backup solutions for small and large systems. The backups itself are written using standard *nix tools and can be used to restore even without amanda itself. The backups can be written to real tapes, disks simulating a tape changer, and into the cloud using Amazon S3 storage.
Because using amanda can be complicated and simple at the same time, I have split the whole story in three articles. The first is about the server part, which is also good for single machines. The second adds a *nix client, and the last article describes some practical commands such as maintenance and restore data.
You may expect an article about Amanda Recovery Manager, this is a backup solotion for your MySQL database and is a better alternatice then what I have written in the MySQL article.