I think the process u have taken is okay ! If possible consider Network Accessible Drives (NAS). They are cheap and reliable. Then u may use ROBOCOPY (a small tool, absolutely free) from Microsoft in conjunction with Microsoft Scheduler to backup files to the NAS drives. I hope u have to use ntbackup…. Another way is Volume Shadow Copy Technology.
This is a new technology in Windows server 2003 that did not exist in Windows server 2000 It is used to create a copy of original volume at the time a backup is initiated. Data is then backed up from the shadow copy instead of the original volume.