I have helped many people recover from virusi and one thing that almost always holds true is that they have not backed up their data. Your computer contains photos, documents, and email that you most likely want to keep.
There are many different ways to backup your data. 2 of the most common are backing up files to your CD-RW (etc) or an external hard drive. These methods are fine but also require you to rely on the media and rely on storing these off-site (bank box, family member house) in the event of fire etc.
Carbonite (or like services) will backup your data directly from your computer and store it on their secure offsite servers. This is a no-brainer. The cost is minimal and gives you the quick and easy way to backup and restore your files.
