That is a great age to take your kids, they're still young enough to be totally overwhelmed in the magic, but they're old enough to appreciate all of the amazing things there are to do and see, and remember it too!

Also, I think PhotoPass will definitely help you guys document your trip in a really simple and great way, especially since it's your first trip, and you get really good shots with all of you in the pic!
In Magic Kingdom, don't miss:
- Peter Pan's Flight (this ride is a classic, and really fun!)
- It's A Small World (simply a must do

)
- Dumbo the Flying Elephant (how can you miss it? haha)
- Mad Tea Party (a personal fave!)
- Splash Mountain (my absolute favorite and so fun for everyone!!!

although I believe it will be closed for refurbing

)
- Big Thunder Mountain Railroad (DD9's fave- it's a blast!)
- Space Mountain
- Buzz Lightyear's Space Ranger Spin
- Pirates of the Caribbean
- Jungle Cruise (so fun and the CMs are hilarious!

)
- The Magic Carpets of Aladdin
- Wishes (fireworks)
In Epcot, don't miss:
- Soarin' (also a favorite, it is incredible!

)
- The Seas with Nemo and Friends
- Test Track (your son will most likely LOVE this!)
- Imagination with Figment!
- Illuminations (the fireworks in World Showcase- they are awesome!

)
In Hollywood Studios, don't miss:
- Toy Story Mania! (this is also a fave, it's just fun for everyone!)
- Rock n' Roller Coaster (depending on how well your kids like thrill rides- this could apply to Space, Splash and Big Thunder in Magic Kingdom as well.)
- Tower of Terror (again, it depends)
- Fantasmic!
- Muppet Vision 3-D (I LOVE this- it's just so cute and funny!)
- Backlot Tour
- The Voyage of the Little Mermaid
- Art of Disney Animation
- One Man's Dream (we love this! it's really interesting!)
- Beauty and the Beast
In Animal Kingdom, don't miss:
- Primeval Whirl
- Dinosaur
- Kali River Rapids (although I believe it will also be closed for refurbing, so nvm!

)
- Expedition Everest (again, depending on how much they like thrillers)
- Kilamanjaro Safari
- The Festival of the Lion King
- Finding Nemo: the Musical
- Camp Minnie-Mickey
- It's Tough to be a Bug!
***In Magic Kingdom, don't miss Toontown either! Because it's officially closing in February

***
I hope this helps! Happy Planning!
