Well, I am currently a student in AP Computer Science A (although my teacher gives me AB work, and AB tests). And, my book, covers A and AB, and it starts from the simplest form of programming. It's meant to teach people who are just starting out. So i dont know man. Look into getting another book. Or ask your teacher for help.
Not an add
I'm not trying to advertise, but I'm currently using "Sams Teach Yourself Java 6 in 21 days". It was the first and only book (so far) that I bought and I have gained all my knowledge out of that single book.
Good luck. ;)