Congrats on the first trip, they're always amazing!
This is what I'd do with kids your age.
MK (2 days, 6 FP)
Meet Anna and Elsa at Princess Fairytale Hall
Enchanted Tales With Belle
Peter Pan's Flight
The Many Adventures of Winnie The Pooh
Festival of Fantasy Parade
Main Street Electrical Parade
HS
Toy Story Midway Mania
Beauty and the Beast - Live on Stage
Fantasmic (if you don't get the F! dining package)
Also, I'd personally suggest skipping Epcot for Animal Kingdom. Epcot is great for adults/teens IMO, but less so for the young ones. We slotted 1.5 days for Epcot on our first trip, then down to 1 day on our second, and on our next trip it will be a half day park. Really the only reason we're even bothering with Epcot is we love Akershus, much better than CRT.
If you have to do Epcot, I'd do
Turtle Talk With Crush
IllumiNations: Reflections of Earth
The Seas with Nemo & Friends
Although I'd much perfer
Animal Kingdom
Kilimanjaro Safaris
Festival of the Lion King
Finding Nemo
Also, the two parades I have selected for MK probably aren't popular with most, but I loved them. They are feet from the entrance to the castle, and the pics we got of the kids with the parade going by, with the castle right behind them were amazing. Show up a little early for curb side seats.
Most of the ones I chose are pretty popular and have longer waiting time. Look through here if you want more info.
http://www.disboards.com/showthread.php?t=3143281