Hello Cazzie.
The type of backup necessary is a subject on which no two experts would agree except that backup is absolutely necessary.
Some users prefer to simply burn their data files to cd\dvd for backup which means that, in the event of a catastrophic hard disk failure, the Operating System and user programs must be re-installed on a new hard disk before recovering the user files from cd/dvd.
Other users prefer to backup entire hard disks by ghosting (cloning) them to various media (my preference is to a dedicated hard drive) so that if necessary the backup disk can simply be installed and in most cases booted from.
How and what you backup depends on how critical your program/data files are to your everyday operation, what facilities are available to you and how much you want to invest in backup. If it's just a simple matter of backing up music/photographs/e-mail folders then you might only need to invest in one cd/dvd at a cost of say $1.50, and burn your files to it, then rely on being able to reinstall the Operating System and user programs from existing media. If you want to backup the tax records for your company spanning the last 10 years your backup system might have to become a bit more sophisticated.
Whichever backup system you opt for ensure that you test the backup files. There's nothing worse than needing to access backup files only to find that they cannot be read for some obscure reason.
Only you can decide what and how and how often you will backup. The software necessary to backup data is free for download so no super-sophisticated program costing zillions of dollars is needed. If you want to backup your entire hard disk I recommend ghosting (cloning) to another hard disk be it fitted internally or in an external enclosure. You may not want to invest the cost of a dedicated hard drive.
Good luck
