Yadis! Backup is a lightweight tool that will automatically back up the files and folders you specify.
You can set the program up in just a moment. Point it at a folder containing files you'd like to protect, Pictures maybe, then a destination folder somewhere else where the backups will be stored, allow the program to carry out an initial backup if you like, and that's about it.
There's no need to worry about scheduling, because Yadis! Backup only works when it's required. If you did specify the Pictures folder, say, it recognises when you add new photos or edit existing ones, and automatically copies those files to your backup location.
If you prefer the security of scheduling, though (or just want to ensure backup operations are only ever carried out when you're not around) then the program can also run backups at some predefined time.
And while the backup is in principle very simple - Yadis! simply copies the files, without any encryption or compression - you are able to turn on versioning, and choose how many versions of a particular file you'd like to keep.