http://www.hawaiitravelbureau.com/mauitours/hana.html
2. The little new moon shaped island is on many postcards - ask anyone local. There are many snorkeling/scuba diving tours that take you there. Maui is not that big.
3. Kihei has some quieter beaches.
4. Take a walk around Lahaina town.
Maui is not my favorite on all Hawaii islands. Personally, I like Big Island better, especially the Helicopter ride to see live red lava flow from the volcano - a must. Tropical beaches all look the same after you see a few of them.