I second the Unofficial Guide suggestion

--If you are not doing the Early "extra magic hours" then avoid the park with EMH. UG will give you access to their crowd calendar online (they post current month free to everyone but the entire year is accessible to those with the current guide book). You can also get from the library if you don't want to buy.
--Decide must-do parades, shows and firework displays. Check dates that they run (ex: Spectromagic and Fantasmic do not run every day of the week). Both of those are excellent by the way.

--Figure out a rough idea of which park which day, when break-time will be and where you will go in the second part of the day (if you have park hoppers).
--Now you can plan your dining with a better idea of where you will be. Look up the menus to assist you with likes/dislikes and to ensure that your toddler will not be eating chicken tenders at every meal!
--While you are looking at menus think about where you might like to eat CounterService as well. There are several great threads about favorite CS restaurants.
--Look up height restrictions, or use the guide book to let you know where you will have to go solo and which rides will be family rides
--Don't try to schedule out the entire day. With a toddler you will just stress yourself out and will miss some of the fun unexpected things, like character interaction. DO have a bit of an idea what you will do when you first arrive at a park.. EX: get Fastpasses for Splash Mtn and then head to Flying Carpets, do Pirates of C. if FP time is not ready..then do the baby swap for SplshMtn so you both can ride.
For some reason PeterPan always has the longest lines...maybe get FP for Winnie the Pooh and ride PeterPan first?
--When your plan is not working, be willing to throw it out!
--First Trips are extra Magical. Have fun!
