Looks like Vanessa has you covered!
Like she said, I recommend doing a little reading/research ahead of time to decide what the "must do's" are for each kid. That way, you can make those things a priority. For example, some characters only meet at certain times throughout the day, and the shows all take place at different times and sometimes on different days. I highly recommend
this site for info. on character meeting times and shows/entertainment. It's updated far more frequently and is often times more accurate than Disney's own site. You might also want to get an idea of any ride closures before you go. I've witnessed many a family become extremely angry/disappointed when they realized a certain ride or attraction was closed for refurbishment. Allears.net is another good site for general WDW info.