Maui is terrific, but you and they would probably also love the Big Island. Perfect age for Volcano National Park (walking through Thurston Lava tube, seeing the huge crater venting, viewing the sea arch, checking out the craters on Chain of Craters Road, etc.). Lots of beaches, places to explore, yada yada.
Condos are great for families (kitchen, etc.): check out http://www.vrbo.com/413069 (I stayed there, and loved the location in Waikoloa Resort; a turtle bumped into me when I snorkeled in A-Bay!)

We've been to both and I'd stick with your original plan except to add I'd skip Oahu unless you have over a week to spend on Big Island.

We also loved A bay. The turtles were a big hit with everyone in the family.
Don't forget the manta rays!
http://www.gohawaii.com/big-island/guidebook/topics/manta-ray-diving

Maui is best for golf and has lovely beach resorts. Haleakala National Park is the highlight for nature but it is incomprehensibly big and kids will not be amused. I prefer the Big Island. I recommend the Hilton Waikoloa Village as the ideal family resort anywhere - period. The buildings are well separated and you park outside the resort. Then go to your building by train or boat. The corridors are lined with art - statues and paintings. The outside areas have trees loaded with beautiful birds and flowers abound. The beach is a lagoon full of water toys and kids who will want to go nowhere else. If you need surf with your sand, which is important, go north to Hapuna Beach, where there are change rooms and life guards. The best beach of all is a secret that I will share if you don't tell anyone. It used to be called Beach 69, not for the reason you think, but because of the highway milepost. But it's now a state park with a road, change rooms, showers, water and a beach with shade, coral, and gentle waves. The road to it runs off the same road as Hapuna Beach, old Puako Road, at Waialea Bay. It is the first paved road that branches toward the ocean from Old Puako Road coming from Hapuna. If you are staying at the Hilton, you don't have to eat all your meals there as there are two small shopping areas with a variety of restaurants. You could spend the entire time there. The big attractions are the Hawaiian Volcanos National Park and the Mauna Kea Observatory. Unless your kids are extreme naturalists, I would avoid the long drive to those places. Instead, enjoy the beaches. Oh - and you didn't mention Kauai. That is better for kids than Maui. And there is absolutely no reason to go to Oahu for more than a day. You can go to Pearl Harbor from the HNL airport very easily. As Oscar Wilde said about Niagara Falls and honeymooners, Waikiki Beach is the second biggest disappointment of the trip. But since its not a honeymoon, it will be the greatest disappointment. It's like going to Chicago on a bad day.

Get thee to Big Island.

There is no way to go wrong in HI. They've never been to Maui so they will only know what a great time the BI is.

Took our kids to Maui twice and they had a great time but there is alot to do on the BI and I think they'd like it there too.

Thanks for all the supportive comments. I will stick with our plan to go to the Big Island.

Not sure if we should hit Pearl Harbor/Oahu at the front end or back end of the trip? Any thoghts? Then we will head to the Big Island.

I want to stay up in the Waikoloa area. So, the big question is do we try to do VNP as a (very) long day trip or do we stay down in that area for a day and then head north? Any thoughts?

Thanks!

I think choosing the Big Island is a very good call. VNP as a day trip would be a very long day but doable. We stayed in Volcano (without checking out of our hotel room at Waikoloa). It was nice to relax that evening rather than driving back. I'd stay overnight if possible.

I would try to stay in Volcano. The biggest downside to the BI with kids is that it is so big and the car rides are long. And when you're 8 or 9, who wants to be in the car when you could be at the beach?

We've overnighted on the Hilo side twice on trips to BI and I highly recommend it.
There's more to see and do than a day trip allows for plus it's a very long (and slow) drive.
Kids are usually OK if you stop and let them stretch their legs .. there's a smoothie stop, a botanical garden stop, a waterfall, Akaka Falls with a short hike, etc.

Maybe visit the VNP in the evening if the lava is glowing or save it until the next morning or do both..

It depends on the amount of time you have on the Big Island. Overnight near the Volcano would be good because you will want to hike Thurston's Lava tube.
There is an old sugar cane ditch ride (Kohala Ditch Adventures) on the north side of Big Island that might be fun for the boys.
Ideally it would be great if you had at least 3 nights,to "resort" at poolside in addition to above.
Not sure how old you need to be to do the manta ray snorkel at night- the boys might think it is cool, or they might be a little frightened.
It might work well if you flew into Hilo and spent first night near Volcano, then two nights on the Waikaloa side and fly out of Kona.
I think do Oahu first- Pearl Harbor, Bishop Museum. If you have time drive along coast from Diamond Head to Kailua which is spectacular and if you are here in early to mid-March the whales may still be around. A short hike up Makapuu is usually a good place to see them.

SHUT UP! About beach 69

Don't know if it's still there, but a few years ago I loved visiting a seahorse farm on the Kona side. It was a huge hit with the kids who were there -- and having seahorses curl their tails around my finger, and seeing the babies, made me feel like a big kid .

Doesn't seem to be on many people's radar, I think it's a must for kinds.
PS. The Kona side is definitely still there; it's the Seahorse Farm I'm not sure about. HAHA!

The best beach of all is a secret that I will share if you don't tell anyone. It used to be called Beach 69<<<<

It sure wasnt a big secret the last time I was there...and sure is a great snorkeling spot. Anyways, back on topic. I would say without reservation Maui would be a better destination

I haven't been on the Big Island since the late 70s, so I ask this question honestly -- are there beautiful [natural] beaches on the BI like Ke'e Beach on Kauai? I mean fluffy white sand, clear water, great surroundings, tropical feel?

Sf, yes, but there on the west side of the island and in the Kohala resort area. The area around Kona is more lava rock and less sand, but there are big, sandy beaches on the BI, they're just concentrated in the Kohala area.

I prefer the BI to Kauai, mostly because the weather is more dependable and the snorkeling is so much better on the BI. But the trade offs are less green, especially where the beaches are located, and a lot more driving.

"there" should be "they're" (geez.)

People say dumb stuff all the time. Stick with your plans for the Big Island.

Have the people who are telling you this been to both islands? Or only Maui?

thanks kureiff - I remember some amazing snorkeling near Kona!

Seahorse Farm is still there. It's a great place for kids.

http://www.seahorse.com/

You might also want to hike Ke Iki Hale (now called Kilauea Hale) - the "little volcano". It's close to the great visitor's center at the Volcano - and you walk through a rain forest, down into the floor of the small cauldron and then across for a mile or so and up and out the other side. Now it's been dormant since '59 - but when the steam hisses up through a vent - you do pick up your step a bit. see http://www.everytrail.com/best/hiking-hawaii-volcanoes-national-park and besides the Volcano Village Inn (maybe a bit expensive for a family) see http://www.volcanovacations.com/index.php?inc=house&id=75

And at the Volcano visitor's center - check out the Ranger talks/walks, and see some of the interesting/historical movies in the theater.

And I would recommend you start on busy Oahu first - and then kick back on Big Island. Assuming your group is going to snorkel - check out the Snorkel Bobs (also check coupons for deals) - and you can rent equipment for a week and take it with you to the next island.

If anyone has not snorkeled before - or even for a good review - try the equipment on at the hotel pool to get used to breathing and swimming with a mask/fins, and also be sure they don't have any hair under the mask - which lets beads of water into the mask/distorting the vision.

And right there on Oahu - 20 minutes south of Waikiki- is the best snorkeling in Hawaii - at Hanauma Bay. Go early to beat the crowds.

There is also a very good public park/with lifeguard - about 4 miles south of Kona town on BI.

See http://www.letsgo-hawaii.com/snorkeling/ and http://www1.honolulu.gov/parks/facility/index.htm

BTW Kure: There is very good snorkeling on Kauai also, as well as Maui, Molokai and Lanai.

You might consider an overnight in the Kapoho or Pahoa area; near enough to do VNP, and you could include the lovely (and really cool for kids) Lava Tree State Park or snorkel the tide pools. Go home to Waikoloa via the northern route, stop at Akaka Falls, then Waipio Valley overlook, and take the Old Mamalahoa Highway (lava caves along the route; keep your eyes peeled) to where it joins with the main hwy in Waimea.

I've snorkeled on Maui and it was good...lots of turtles! I carried my snorkel gear for 8 days on Kauai, and while I'm sure there is good snorkeling, the surf was too rough for any snorkeling the week or so we were there and that was in May. Others may certainly feel differently from me, but out of the three islands I have visited, I prefer the BI for snorkeling.

Wow. I really appreciate all the advice and suggestions. Trying to sequence the trip. I guess we could start in Oahu for one or two days and see Pearl Harbor, Chinatown, etc and then head to the Big Island. Our thought is to rent a condo for a week. So, the question is do we tack on another day or so at the end to do VNP or do just double book ourselves one night and do VNP some point during the week. I am guessing the later as Spring Break isn't that long.

Now, to book and get it all sorted.

Thanks

If you do stay in this area (http://www.vrbo.com/413069 in Waikola), you can take Saddle Road eastward to Hilo, check out Kaumana Caves Park and the free zoo with the white tiger!

I think that it is more relaxing if you keep the logistics simple especially with children along.

The driving on the Big Island is pretty fatguing because they are two lanes roads. The distances from point A to B is significant.

Given so many options I would narrow down your focus to two bases, one on the west side Waikaloa and the other on the east side Volcano or Hilo and enjoy your days without doing too much driving. There is enough to do on the east side to warrant a couple of days.

taitai, you may want to read kurieff's trip reports to Hawaii. The info may be helpful in planning your trip with kids. I agree with building in lots of time for relaxing. The idea to double-book a room in Volcano mid-week really worked well for us too. We were able to take a leisurely drive around the island from Kona (traveling clockwise) and loved having the whole day to get to Volcano. We spent the night in a beautiful location, went to VNP and then drove back to Kona the next day. We fit in a lot during those two days but didn't feel rushed or stressed. It was a good solution for us. We ate at the little Thai restaurant in Volcano and it was WONDERFUL!