bee, a word of warning. The parks are incredibly busy especially at Easter, remember it's Easter all over the world and all the kids are off.
Why not go at Whitsun and take them out of school for the 2nd week. We did that last year and didn't suffer with the queues.
If you don't stay at a Disney Hotel I'd recommend you stay at Lake Buena Vista. Try and get a room with a kitchenette so at least you can make cereal and have drinks in the room. Kissimmee is very popular but whatever anyone says about it being next door to Disney it isn't. You will drive for at least 25 minutes to get there, the traffic is pretty bad and they have been resurfacing the 192 for 2 years.
If you stay in Lake Buena Vista (admittedly more expensive than Kissimmee) you'll be near Downtown Disney which is great fun and Premium Outlets (if you like shopping).
The parks can be pretty intense and exhausting if it's hot (which no doubt it will be). Do a park every other day and set off early.
After going through the gates at WDW it will take 30 minutes to get to the entrance. Remember this when you set off. You'll park the car, get on a train then on a monorail or a boat over to the park entrance.
If you plan on going back after this visit I'd suggest you go to Sea World, Walt Disney World, Animal Kingdom and Universal Studios this time and leave the rest for another trip.
You must definitely book a Character Breakfast at the Contemporary Resort (Disney Hotel). Book it when you book your holiday for a day when you have a couple of hours free. It's a all you can eat breakfast buffet and all the characters visit your table for photos and autographs. You don't have to stay at the hotel to have the breakfast.
If you're going to a beach I'd recommend Treasure Island, St Petes or Clearwater all on the west coast.
You must be falling asleep, tell if you want more. R