I am actually taking AP Bio right now. The reading just sucks... but stick with it. You need to know the chapters by heart. Know the diagrams in the textbook, Read READ READ!, and do practice questions.
Like someone mentioned above, read the chapters over like 5 times (literally) so that way you know the information by heart. All of the tests I take in Bio class are timed, so I literally have like no time to think, and I'm often forced to spill out everything I know.
Bio is my first AP class, and I've found that it is a lot of work and reading. Manage your time and you should be fine