In tip 2265, I described how to schedule a backup without having to manage the media.
See tip 4113 » More on Windows 2000 backup command-line switches..
See tip 4207 » How do I manually edit a Windows 2000 Ntbackup script?
Microsoft Knowledge Base Article 300135 contains the following summary:
This step-by-step article describes how to configure Microsoft Windows Backup to run automatically at a scheduled time.
NOTE: Only the basic backup operations are covered in this article. For information about more advanced topics,
such as tape libraries and media pools, refer to Windows 2000 Backup Online Help.