I assume you are talking about the fixed wing part of the course.
Handling the Big Jets is a perennial favourite. Darrol Stinton's books, especially Flying Qualities and Flight Testing the aeroplane are also excellent.
The FAA Advisory Circulars on Parts 23 and 25 have absolutely no character development or plot, but are good on the subjects.
If helicopters are your bag, I might modestly recommend my book - "The Art and Science of Flying Helicopters", and any of the books by Ray Prouty as well.