S.M.
We took our son there last year after speding 4 days at Disneyland and California Adventure. It was such a great experience after the huge crowds we found at Disney. We stayed at the Homewood Suites a couple of miles from LegoLand. I would highly recommend it. The offer a free breakfast every morning and during the week days they offer a FREE limited dinner. My husband works for Verizon. They have company discounts at some attractions. We got buy a day get a day free at LegoLand through Verizon. We will probably go back next year, but do more things like the zoo and Sea World instead of Disney.
Your family will have tons of fun. Like some of the others have said, pack either a change of clothes or swim suits and towels for the waterpark area. (I wish I had been more aware of that last year.) Have fun!!!!!!!!!!
S.