It depends what area you're interested in reading up on. If it's the actual flying that you want to read about, you could do worse than buy a copy of Trevor Thom Book 1, which is the syllabus your instructor will follow when you get your Private Pilots Licence (PPL) - the first step to becoming a commercial pilot.
Books 2, 3, 4 and 6 in the Trevor Thom series will also be useful - they give you the theoretical knowledge that you need to pass the exams which go with the PPL.
Or, if there's a specific area which interests you, let us know and I'm sure someone will know of a suitable book.
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