Jim,
If you are asking how to back up personal data files
(like doc's....etc) then you simply copy them to a CD.
To do that you'll need a CDROM recorder and recordable
CDs. Each CD will hold 650+ mb of files. The CD
recorder will usually come with software that will guide
you through the process of saving copies of important
files.
On the other hand, if your asking how to backup your
entire computer (all the programs, files, system....etc)
then you'll still need the CDROM recorder and CDs but
you'll also need a program called Norton Ghost. That is
the best program out there to do a complete backup.