If you are going to Florida for a full JAA course then I should like to think that ALL training, Air & Ground including formal exams are included - you need to check this out.
Any advanced reading has got to be a bonus.
You need to be commercially aware that flying schools make their money flying and not on ground school. Not all flying schools will run formal ground school training. Cost can vary from as little as £80 per subject to £25.00 per hour. That's if you can find one to play ball with your plans.
All the Thom books are worth getting but for the PPL you could ignore Radio Navigation & Instrument Flying (Book 5 I believe).
All the best.