Backups:

-Make sure to back up regularly; Backup as often as needed to prevent a disaster if the programs or data was lost. 

-There are many ways to backup, consider doing more than one:  Copies on computer itself, separate hard drives, tape drives, burn to CDs/DVDs, and online.

-Test the backups! Take a few minutes and make sure that information can be restored from the backups.  One of my clients backed up his data every night on tapes but even with me begging permission to do a test restore, the tapes were never checked.  One day I got the call that the computer crashed and they found that every tape was blank, nothing on the tapes at all.  Do not let this happen to you, check the backups! (The relatively good news in this story is that I made a copy of their data 3 days before for development reasons, so they only lost a few days of information.)

-Keep at least some of the backups in a physical location different from the computer to be safe from fire and theft.

-If you are using a tape drive, make sure to buy a 2nd tape drive test the tapes with it and keep the 2^nd drive off site.  In many cases I have found that the only drive in the world that can read a tape is the one that wrote it, or the tape drive model which has not been made or sold in years.  Unfortunately the tape drive that wrote it was stolen (or lost in a fire etc.) and now the information on the tape could not be recovered, a total lose.