We will be taking our first family trip next Spring- yay!

Just the 2 older kids so they will be 6 and 4.5. I don't even know where to start.
First- when should I officially begin planning?
We plan on staying at the resorts......is there one you like better?
How many days/nights would you recommend?
Which parks would you choose and how long should I plan for each one? I want to skip Epcot. Definitely do Magic Kingdom, obviously and maybe Animal Kingdom?
Basically any advice or suggestions are greatly appreciated! TIA!
Re: Anyone been to Disney?
We were there in April. I booked breakfast at Cinderella's Castle in Dec. (so 4 months out). If your DD's like the princesses it is wonderful. DD LOVED it.
We don;t stay at the resorts.
We did MK for 2 days, Hollywood Studios for 1. HS was great for my kids, they are into Toy Story, Disney Jr and Princesses and that stuff was all there.
Go the parks early in the morning b/c it's least crowded. You can come back to your room in the afternoon for a break. You can't do everything so pick your must dos. Take advantage of extra hours at the parks (you get this by staying on property). Make all dining reservations early b/c you can always change them later.
We took our son for his 4th birthday, to Magic Kingdom. We live in FL so its only an Hr drive for us, so no hotel stays, but if you have AAA go through them for a discount.
Epcot is more for adults. Animal Kingdom I LOVE but then again I really enjoy animals.
Pack a lunch and juice for the kids or snacks so you aren't spending so much in the parks.
If you go during the week its less busy!
First- when should I officially begin planning? Now, as others have mentioned, character dining books out faarrr in advance.
We plan on staying at the resorts......is there one you like better? We really love the Animal Kingdom Lodge. We live in Tampa, but staying on property really makes it feel like we're a long way from home, esp. at AKL. You can get a savannah view room, come home after the parks, chill on your balcony with a glass of wine watching giraffes, etc. A lot of people don't like that it's far away, but I liked that. Felt more peaceful. It doesn't have the convenience of some resorts where you could walk or monorail to some parks, though. But it does have fantastic pools, and I highly recommend that you plan to spend at least one or maybe more afternoons at a pool rather than the park. You'll need that, trust me.
How many days/nights would you recommend? At least 3 days, 4 nights. Not less.
Which parks would you choose and how long should I plan for each one? I want to skip Epcot. Definitely do Magic Kingdom, obviously and maybe Animal Kingdom? While I love AKL, I'm not a huge fan of the park. Maybe it's because we have Busch Gardens here in Tampa, and BG is much, much bigger and the crowd is more manageable, so it's just a better experience?
I really like Epcot, and I humbly suggest you give it a little more consideration. Soarin' is - imho - the best ride in any park anywhere, ever. It's just awesome. You have to get a fastpass, though. The fireworks at Epcot are fantastic. Probably the best food around, too. There are a lot of lame things at Epcot, too, I suppose. While I generally would stay away from park hopping, you could get up early, go to Epcot, do the Akerhaus princess breakfast, send someone for fastpasses for Soarin, cruise through the World Showcase, head back to your hotel for a break, and then hit a different park for the evening. That would probably be enough time for Epcot.
Basically any advice or suggestions are greatly appreciated! TIA! Pick a must-do things, and I mean a FEW, like 2 total for each day. Do those, and everything on top of it is just gravy. There's just too much and the more you can simplify your experience, the more you'll enjoy it. Also, let the Disney photographers do their thing, and get the card for them to scan. You don't have to buy squat, but if you can if you want to, later, online. It's a nice option to have.
My silly Lily is almost 4.