Get the Passporter book. It has stuff in there rated by little kids, teenagers, and adults. And it has EVERYTHING. If you haven’t made dining reservations yet you’re probably out of luck for the best restaurants.
If your daughter likes Princesses, the breakfast at Akershus at Epcot usually has spots open if you walk up. Make sure you pack a princess outfit for her–even if it’s just a nice dress, almost EVERY kid wears a costume there these days. Unless she likes dark, loud rides, pay attention to the signs. Dinosaur is fucking terrifying to small children, but it’s set next to the most kid-friendly looking amusement park thing so there’s always at least one kid wailing in terror having just gone on it.
For the older boys, hit the three mountains (Thunder, Splash, Space) at the Magic Kingdom. Make them ride Buzz Lightyear together even if it looks like a kiddy ride. Find the make your own Space Mountain thing at Epcot and DO IT. There’s a similar one at Disney Quest too. If they like arcade games go there.
Typhoon Lagoon’s wave pool is amazing and there’s shallow areas for your daughter away from the crush of wave riders.
Take a break in the afternoon to go back to your hotel for a swim/lunch/nap and don’t push yourselves too hard. Disney is exhausting.
Make sure everyone has comfortable sneakers packed. Or Crocs. Even the most comfortable sandals might start killing you after a day or so.
And SHAMELESS PLUG FOR MY TIPS SITE.
Hands down best character meet and greets is, strangely, the Animal Kingdom. Hit up Camp Minnie Mickey when Festival of the Lion King starts and you will pretty much have about 7+ characters to yourself, including the Big Four.