Here is a nice video of Maui. BTW the best beach for children is the small beach at the Lahaina Jodo Mission which is very close to Lahaina Cannery. It's just south of Mala Wharf.
A snorkel tour to Molokini. This is a small atoll south of Maui and has some of the best snorkeling in the islands.
Here is a video of the south Kihei area.
The Makena beaches have some of the best sand. Warning: There may be nude people at the small beach.
The waves (at world class surfing beach Hookipa which is east of Paia) can be huge.
Wailuku Town is the govermental center of Maui, and is the gateway into Iao Valley.
The volcano of Maui is Haleakala.
Iao Valley State Park is a beautiful place and when it's raining there are a lot of waterfalls to see. Alas, the increase in local and visiting populations has led to decreased access to the inner region.
Unfortunately, Kapalua is really a colony of outsiders on Maui. A beautiful area though. World famous golf courses. R.I.P Pineapple Hill Restaurant, at one time, one of the best restaurants on Maui.