You might check out the following in your research:
1-The Carrying Passengers for Hire Study Guide, on the Utah State Parks commercial boating section. stateparks.utah.gov/resources/boating/general
In order to attain a Whitewater River Guide license, one must document 9 whitewater river trips, plus take a written exam, as well as hold advanced first aid/cpr cards.
2-Colorado State Parks. You have to dig a bit here, but the River Outfitters License section will have some relevant info on river guide and on guide instructor qualifications, as well as regs about gear needed on commercial trips.
3-Northwest River Supply. bottom of the page, click Learn, then Rafting. Stuff here on entrapment, selecting a raft, and others.
4-Whitewater Voyages Guide School. Whitewater Voyages is a long standing California based company. The original owner, William McGinnis, wrote three books that I still consider classics. The basic info is relevant.
"Whitewater Rafting" William McGinnis, 1975
"The Guide's Guide: Reflections on guiding professional river trips"
"Class V Briefing"
Doubtful most libraries will have them, but to purchase cheap try AbeBooks Official Site - New & Used Books, Textbooks, & Rare Books
. order from 5 star sellers.
5-last, "The Complete Whitewater Rafter" can still be had in some river stores. Again, a bit dated but lots of relevant information.
Good Luck. Sounds like an interesting project.