Always make sure you have a way to restore the information from your backup to the main system, that doesn't involve using the backup itself. If your restoration program is saved as part of your backup copy, you might not be able to restore your data in a crisis - because to do the restoration, you need the software that has to be restored! It becomes a 'catch-22' situation. Usually, having the installation disks for your backup program will prevent the 'catch-22'.
Always test the restoration process of your backup. If you have a spare computer, test restoring on that. Otherwise, test it on a separate folder on your main computer - make sure it doesn't overwrite your primary copy of your information!
In a perfect world, you test your restoration process by getting a blank computer, as if you'd lost your computer entirely and were starting from scratch. Install the operating system, your main programs, and your backup program from their original disks. (make sure those disks are still for sale! If your office or home burns down, your insurance company will be buying them for you - assuming you're insured.) Then restore your information from the backups, using the instructions given in the backup-program's manuals.
In the real world, do as much of that as you can. At minimum, restore the information from your backup tapes (or whatever) into an empty directory of your computer's hard drive. DO NOT overwrite your current information!
Be aware that you will probably need to use exactly the same backup program to restore your data as you used to save it. If that program becomes unavailable, you will need to check with your local computer-knowledgeable person whether you need to change programs, or to keep a copy at each of your backup-storage locations. If you do the second, make sure you won't need the backup-program just to install the backup program!