|You can either backup individual files or the complete system, one or the other. I wouldn't bother as most of the system files can be restored by the operating system if you need to do a reinstall. |
Backing up the entire system on a daily basis is just a waste of time and space. Once a month should be enough.
The best plan is to do an incremental backup once a day where only files that have changed are backed up then a complete backup once a month, then start a new incremental file archiving the old on on CD/DVD.
There should be a scheduler to do different types of backups and daily, weekly and monthly basis.
You could adopt the Grandfather, Father, Son principle of backup rotation. This ensures that you have a full backup to fall back on if anything goes wrong as backups of the latest changes as well.