I don't think I've ever heard of someone doing such a thing even on a Windoze box.
I think you are going to have a hard time finding information on this as most folks don't try to hook up hardware like scanners to SME. My best suggestion would be to look at what it takes to hook a scanner up to a RH desktop box and go from there
Why can't you simply move the scanner from PC to PC?? Hooking a scanner up SME (if it's possible) would require that you still install all of the scanning hardware on the client and would require you to run back and forth between the server and your PC between every scan.... Real pain.
Greg