Oh my gosh! I hope you have the time of your life! We leave a week from today for the big island. I have no suggestions cause I have never been there. But wait I do have a suggestion (duh) Get "Kauai revealed" book. It is so good for going to the off beat places. We have one for the big island and it truely takes you to hidden (or used to hiden )places. We saw some really neat places. We had to walk and climb a bit here and there but we found magical places!
http://www.wizardpub.com/kauai/kauai.html you can not go wrong with this book. I got the one I have on ebay for pretty cheap. It was used but who cares.
This guide book led us to places called mermaid ponds, which were so magical they made me cry. Also it lead us to the best ice cream sunday I have ever had too. Please let me know if you get this I would like to know if it is as good as the one we have.
When do you go?