If you for some reason have a urgent need of having the backup job at a different server than the database, there are many tools available for you doing just that. Symantec Backup Exec is among those that have a SQL Server Agent.
However, I personally find that it's better to have SQL Server taking backup to file, and then have my backupapplication backing up that file to tape.
Well Martha, if you are a complete novice to backup you definitely NEED to have a look at how backups in SQL Server works, no matter what tool you are using. I've just seen SO many occurances where the backup knowledge is inadequate. You'll need to have a look at both database backup and log backup, and have a fairly good knowledge about how it all ties together.