http://www.wakeworld.com/FAQ/ Q. How should I adjust my bindings?
A. Beginners will place the bindings closer to the rear of the board in order to sink the tail fin deeper in the water for better control. As you improve with stability, balance and control, you can move the bindings closer to the center/front of the board making it easier for surface tricks, fakie, and even in landing bigger wake jumps. It really depends on the board and how it responds to you. As for the angle of the plate on the board- it should at least be somewhere comfortable, not pigeon-toed or duck-feet but what feels good for you.