K.L.
I always recommend the Unofficial guide to Disney. It was my "bible" when we went. tells you everything you want to know. Haven't been to HP so I am jealous. Be prepared to put some time into researching/planning this trip if you want it to be a success. I do recommend taking some time in the middle of the day, going back to your hotel, and take a rest or cool off in the pool. then go back in the evening. Make some plans for your meals; we ended up having to wait for hours for a table our first nite there so that was a drag.