Last year we stayed in Maui for a week last year. It is a lovely Island, although it was very windy all the time we were there. We stayed in a Condo on the Golf Course at Kaanapali Beach across from a great shopping centre 'The Whalers' and the beach with all the big resorts.
We drove on pretty much every road on the Island, even the very narrow one around the top of the Island (don't think we were supposed to be on it). When we got to the top there is a lovely shop/gallery where you can buy T-Shirts "I survived the Road" - that says it all!
The Hanna Road gets all the good reports, but is very winding, narrow and nowhere to stop a lot of the time to take pictures of the beautiful views. We were advised to take a packed lunch, but except for a couple of stops at the Arborium (lovely) and waterfall, we got to Hanna at lunchtime and found a beautiful hotel. I don't know if you have to fly in to stay there, as you wouldn't want to drive the road too often they way some others drive.
The best drive we did there was to the Volcano National Park to see the Haleakala Crater. Absolutely amazing but windy up there, one of the most interesting Volcanoes we have been to (although dormant). Better than the one on the Big Island.
The best snorkelling spot that we went to is at Honolua Bay, a drive north of Kaapalani Beach. Black rock is well known, accessible, but not as good. On the other side near Wailea, Makena Bay is also quite good with the odd turtle around.
A lovely shopping centre at Wailea. Lahinia Town has lots of good restaurants and interesting art and craft shops along with the tourist ones.
If you own or manage Maui, register now for free tools to enhance your listing, attract new reviews, and respond to reviewers.