First, the single smartest thing is taking the time to research by using these forums, so congrats, you're well ahead of many!
Sort of a wide open question - check out the Theme Parks & Strategies thread - lots of resources.
My quick thought is to "roll with the child". I've seen many parents determined to see & do everything with little kids who are worn out and NO ONE is having fun! Take breaks - MK & AK have playground areas; and be ready to head for resort earlier than you might want. Recharge batteries with nap (cocktail for you) and go back in evening when cooler.