Ask the training provider for study material to prepare.
It's a simple airplane but the course is usually short (2weeks?) so not much time to learn systems in depth.
OM A won't help much as it is not type specific (JAR OPS1)
If you are going to fly it commercially ask your company for the OM B and start reading your company's procedures (call outs, flight profiles etc)
If you get study material from the training provider concentrate on limitations and memory items first, then have a look at the systems if time permits?
If it is your first type rating it will be hard work, if not it is just like all the others...