Hi Kathryn,
A trip to
Aulani, A Disney Resort & Spa, sounds magical.
As to
excursions, there are so many things to do when you have a home base of Aulani, A Disney Resort & Spa. You might enjoy an excursion to the North Shore and to tour the Dole Plantation. Many also recommend a trip to Pearl Harbor, but especially with your youngest son, you will need to consider how he might react. An excursion to Kualoa Ranch also comes highly recommended. For
dining at Aulani, A Disney Resort & Spa, Makahiki offers a character breakfast and is a nice dining option. It is also a good idea to rent a car when you are staying at Aulani, A Disney Resort & Spa if you are able to do so.
Do not forget all of the great activities that occur at the resort. When at the resort, check the Daily 'Iwa for a listing of these activities. Your boys may also enjoy the activities at
Aunty's Beach House, the amazing kids club.
As to how far in advance to book excursions and dining, I recommend as far ahead as you can to ensure that you get your first choices of activities and dates. To reserve dining, you can use the link that I provided above, or call (808) 674-6200. Instructions for booking excursions are also at the webpage I linked above, or you can call 1-800-840-6820.
I hope that these thoughts are helpful for you Kathryn. Please do write back if you have any further questions.