Yup. Two of my favorites are "Handling the big jets," by D.P. Davies and "Jet Engines," by Klaus Hunecke. Some people like the Turbine Pilots Flight Manual, by Brown, but I found it to be less than helpful. It was way to basic, and most of what I found there was allready pretty common knowledge. Honestly, turbine engines are pretty easy to handle, and the fact that they are difficult is just a myth. The company you will be working for will teach you, and that will be far more helpful than any book you may purchase. PT-6's are not difficult, and neither is the Carvan. The most difficult thing about larger turbine aircraft is their systems, and that's not a problem with the Caravan.
Good luck to you.