AAA and travel agencies sell vouchers that you need to trade for actual passes. I don't know if you get an actual pass from Universal in the mail or you need to still go to a ticket booth. I got a AAA voucher in 2003, since then I just need to call Universal to renew (very easy). Anyway, your pass year starts the first day you go through the turnstiles.
I just read that UOR raised AP prices on April 22. Didn't hear about that before they did it. Sneaky.