I think it is funny that I never experienced a hard drive failure in my whole life. Many friends that I have been talking to did experience corrupt or damaged hard drives and lost data because of this. Did I mention that I do backup my files regulary while they are not ? I could bet a large amount of money that one of my hard drives would fail as soon as I would decide to discontinue backing up my files.
Karen's Replicator is a freeware utility for Windows that makes it pretty easy to backup files automatically. You may specify to schedule regular downloads and include or exclude files on certain backup sessions. It is also up to you to select the source and destination files and locations. I think the best method is to back them up on an external hard drive and additionally burn the most important files regulary on DVD.
A nice feature is that you can select to either backup files normally or mirror the source which would mean that all files that have been deleted on the source will be deleted on the backup as well. The default mode copies only changed files to the backup drive but this can be easily changed to suit your needs.