Jerry will teach his class every day if there are students (except on his off days of course, which I'm pretty sure is Saturday/Sunday.) The dive shop will schedule the class for you if you request it on a certain day. He also teaches the class in three sections:
Beginner- Generally, you talk about the common fish, and he goes through a slide show of the 50 most common fish in Bonaire. Basically, you learn to name the fish you've always seen.
Intermediate- Talk about some of the more uncommon fish. Seahorses, Frogfish, Morays, Pipefish, etc. Learn more about the interraction between fish, and more about where to look for them.
Advanced- Pretty much Gobies and Blennies. What the different species are, and where to look for. It's actually a pretty rewarding class because you start to find all kinds of fish you've never seen on parts of the reef you've always passed over.
All of Jerry's classes are very freeform, and he will spend a majority of time answering your questions if you come with an eager mind.
Tom