Years of making backups has taught me a few things, so if you are going to start taking backups then here are a few suggestions.
DONT just backup everything to one CD or DVD, then do another CD or DVD a few months later. After a while you finish up with a load of CDs, and finding anything afterwards is a nightmare.
So for example, have a set of CDs or DVDs JUST for digital photos. Call the disks DP1, DP2, DP3 and so on. DP stands for Digital Picture.
Try to put the photos in folders for each event BEFORE you back them up. So have a folder called "Holiday France 07", and other "Trip to London 08".
That makes them easier to find afterwards.
Same with music, have disks called MUSIC01, MUSIC02 and so on,JUST for music, this makes it easier to find your music afterwards.
Once you take out your photos and music that mostly leaves personal files like word documents, spreadsheets and so on.
Put them in folders by subject (Bank, Holdiday, Car etc) then just before you make a backup put them all in a folder of the days date.
So call the folder BU20_08_2008 (BU for Back Up).
Next month call the folder BU30_09_2008
Then when you put them on CD or DVD it is much easier to locate a folder for a particular date afterwards.
This sounds like a lot of work, but if you make backups for 4 or 5 years then you will start to reap the benefit when you look for a photograph from 2006, or a document you wrote in 2005.