For backing up just my genealogy data I use a 16 GB USB memory stick and a free program called Syncback. I've setup the task in Syncback to only synchronize the changed data going from my desktop computer to the memory stick. It is quick (1-5 minutes usually) and painless to run ... plug in memory stick, and a couple of clicks later my data is backed up. I then take that memory stick to my laptop and sync that information on the stick to the drive on my laptop so that I have current information on my laptop.There are paid version of Synback, SE and Pro, but Ken advises that the free version works just fine for simple synchronizing of information.
Once you've backed up check to make sure you can recover your files or its all a big waste of time and resources.