I have a readyNAS box and I really think that is the best option out there for small NAS decives. It has 3 roles (for me): a small file server for home (about 4 users at any one time streaming music, videos, and some light video production work), a remote storage location for my real job, and...
what is the drive letter you want to back it up to? Do you want to maintain a mirror of your actual data? Robocopy is fairly easy to get working once you get used to it. If you type robocopy /??? you will get a list of the top 30 or so commands.
However, off the top of my head it would...