[ale] SANE setup questions

[jmills at jmills.gtri.gatech.edu (John M. Mills)]

I have been reading the SANE intro doc and man pages on sane-scsi and
sane-hp, without getting much idea how to use SANE and a scsi interface to
run my scanner (HP 4p).  I would appreciate any guidance in these topics,
starting from the top: 

1) determining whether my SCSI driver actually sees my scanner - I don't
   have any other SCSI devices, and I'm not sure the relevant modules
   (aha152x.o and sg.o for starters) were actually built and inserted
   properly.  'modprobe' and 'insmode' seem to run without complaint, but
   I don't know if anything has been accomplished.  I know that some
   kerneld and module activity are working, as 'lp' was built as a module,
   and printing works.  (2.0.33/ELF/libc.5.* setup)
2) Invoking scanner through scanimage, gimp, or whatever app -- I just
   haven't found anything like a 'usage' to help me, yet.
3) Getting further information - mailing lists, docs, etc.

  John M. Mills, Senior Research Engineer -- john.mills at gtri.gatech.edu
  Georgia Tech Research Institute, Georgia Tech, Atlanta, GA 30332-0834
        Phone contacts: 404.894.0151 (voice), 404.894.6285 (FAX)
  "No matter how long you work on your writing, as soon as you pick it   
   up again, your eye will fall instantly on a typographical error."
                                   - Hugh Denny's Law of report writing