What kinds of files can I backup?

A  Any files that you don't want to lose! A few examples are (email addresses, contact information, accounting information, digital pictures, school work, MP3 files, presentations...this list could go on forever). If you don't choose it you could lose it!
Remember, your data is, by far, the most important piece of information on your computer and therefore needs to be backed up regularly. This is the information that would be difficult (if not impossible) and time-consuming to replace should something happen. Programs and Operating system files can be re-installed from their CD...Your data cannot.
You are billed according to the amount of data that is backed up.