I recommend ``The Complete Rigger's Apprentice'' by Brian Toss .

His book has as much of the theory on knots as a knot user needs to know, great instructions on how to tie them, and, most important of all, great instructions on how and when to use them. He talks about securing timbers, guying a mast, joining ropes, and so on.

It's sail boat oriented, but I think all that's left out that might be useful is the sheepshank knot. I think that's a pretty small loss. It also means that there are excellent sections on decorative knots, using wire rope (you won't want that for your present class, but it's good to know), and much more. I have an earlier version which was excellent, and I've heard that this one is better.