Whether flying is a hobby or a potential career, there are subjects to be studied and exams to be passed - JAR Exams. Your school will have it's own preference and we cover tehm all. To be a Safe Pilot - you need to be informed and fully understand the material. If the book that you are using on a particular subject doesn't explain it sufficiently for you - have a look at a book from another series. You are spending a lot of money on Flying Tuition - don't skimp on the books. They will save you money in teh long run.