Lynn, there are Revealed books for each island. Absolutely great and great directions.
We stopped at the Polynesian Center for lunch and that was it ... I didn't really see much I wanted to stay for ... reminded me of Seaworld, and a very homogenized version of Polynesian life. You make the call.
Here is a link to the photos from our cruise ... maybe they will help you decide what you wish to do:
On the cars, we went through:
and had a great experience in every port. Plus great rates. We rented Dodge Neons and got 'em for $35 a day, with tax. Nice comfy car for two (and I am 6-4). Be sure you click the button at the top for pier pickup. I would *not* spend the money for a convertible (as advised in the Revealed books) due to rain and sun.
Finally, we did see the USS Arizona in Honolulu ... definitely worth it in my opinion. But in this case, I would book the excursion (about $39), because the tour groups get preferential treatment to get on the ferry over to the Arizona. Schleps off the street wait 1.5 to 2 hours. We lucked out and got there when a tour bus was late and got in 15 mins but we were the exception.
Hope this also helps.