Hi Maggie,
Taking your little ones to Disney World for the first time is magical! The look of wonder in their eyes is priceless and something that you will treasure - sounds sappy, but it is so true!
I recommend going with a 5 day package if your budget allows. Otherwise, you'll feel compelled to go, go, go. You'll end up all having melt-downs - not fun. With 5 days you can go a bit slower, take those important breaks to rest and recharge, and still get to see everything you want to see.
Are you getting park hopper passes? That would really change touring plans a bit. I like to spend the morning hours in one park, head back to the resort for a nap, then finish up the evening in a different park. If you simply have one day park passes, I recommend this:Day 1 - Magic Kingdom
- Day 3 - If you're doing the 3 day package, head back to Magic Kingdom. Otherwise, give Epcot a try - there really are some fun things for toddlers to see.
- Day 5 - The park of your choice that you didn't get to fully explore. For me this would be Epcot, but I know not everyone loves Epcot with small children. Be sure to bring a change of clothes. There is a squirting fountain that they can run through, but walking around with wet kiddos is not fun.
Try to make reservations but keep in mind some kids are terrified of characters at that age. Make your reservation at the end of your stay. That way, if you see your children won't enjoy it, you can cancel. The parades and fireworks are beautiful and fun, but they always seemed to interfere with nap & bed time. It's important not to push yourselves to do too much. Keeping some semblance of a normal schedule has always worked best for our family.
Hope this helps. Have a magical vacation!