May not be much help, I'm planning our second trip, but our first with kids. My boys are 3 and 1, so it's mostly geared towards them.
MK-Dumbo, Pooh ride, Buzz Lightyear, Carousel, Peter Pan, Barnstormer, Carousel of Progress (if it's open), Philharmagic, Wishes, and Spectromagic. Also the daytime parade if we have time.
AK-Festival of the Lion King, Kilamanjaro Safari, Triceratop Spin, Conservation Station, whatever else we have time for
EPCOT-Spaceship Earth, Maelstrom, the Living Seas (my 3-yo loves anything related to fish,etc), as much as we can see if the World Showcase, Illuminations, whatever else we can fit in
MGM-Playhouse Disney, Characters at Al's Toy Barn (Toy Story characters), Beauty and the Beast, the Stars and Cars parade, Great Movie Ride, and whatever else we can fit in.
We will be there 8 full days at the end of Sept/early Oct, so I'm thinking we should be able to do quite a bit. There are a lot more things I would like to get to do than I listed, we'll just have to see how things go. We're also going to
MNSSHP and doing several character meals.
I agree with getting a good guide book (or 3 or 4), I have the Unofficial Guide, and I love it. I also borrowed several others from the library because I wanted to see if I'd like them before I bought them. Most of them I didn't like enough to buy. I know with my family, we will not be able to go without a break in the afternoon, the boys would be so cranky and tired, it would not be a good trip for us.
Have fun planning!
Steph