For those in business (and really anyone), nothing is more important than backing up your critical information on a regular basis. If you have ever had the horrifying experience of a disk crash or a paralyzing virus attack (and I have), then you know what I'm saying. Your business can quickly grind to a halt if, for example, you lose customer contact and purchase records, critical projects or WIP, photos, accounting records...use your imagination. Put simply, it can be catastrophic and hard to recover.
At minimum, get a Zip or external backup drive. They are cheap today. I just saw an ad for an external disk drive that offers over 300GB of storage for $139!! Whatever you do, be sure to backup critical data immediately after you create or update it. Better safe than sorry, so make this a standard practice.
A "hands free - worry free" solution is to subscribe to a Web-based automatic backup solution. these work in the background, always backing up new files over the Internet while you continue your work. Obviously, you want to make sure that transmissions are secure and that the repository is itself backed-up on a regular basis.
These online solutions used to be costly, but now they are quite affordable. I use Carbonite myself, which cost just pennies a day. It's a small price to pay for peace of mind. If I ever do suffer a disaster, I'm confident I'll be able to recover and stay in business. ;~)