These are classic introductionary documents for any simulater subdriver:
http://www.subguru.com/missions/SCHQ_TACMAN_PDF.zip
http://www.subguru.com/BluebookR20.zip
But this is site with a more official explanation. The above is based on what is modled in the various sub games (mostly 688i and Subcommand)
See link in Bilge Rat's message below. I forgot to include it.
Look what Google dug up: From our very own Dr Sid:
http://subsim.questions.cz/sopro/doc/sopro.html
His tool to make those neat soundray patterns is here:
http://subsim.questions.cz/sopro/sopro.1.9.zip