Art,
My process is similar. After capture I make two copies on CD or DVD if it is from a digital camera. I don't backup scans anymore. Seems a waste of time and CDs.
I use external Firewire or USB drives to hold images I am working on and scans that still need to be processed.
My Done files go to a Network Attached Storage (NAS) RAID device and are backed up to DVD as well. The NAS holds 4 drives and is expandable by hot swapping in larger drives.
One thing that is very important with hard drives is cooling. None of the external drives I have purchased have a cooling fan. I believe this is the cause of what I consider a very high failure rate for these drives in the last several years. Out of 4 drive purchased 3 have died. I replaced the drives in the enclosure and currently am using two of them. In that same time I have not lost any of the 4 internal drives which are well cooled.
My file names could use some work. Currently I use the names from the camera, or the file number for scans.
Larry