Red hot mamas is a very small burrito stand that was great also a great shrimp truck by bubba burger (dont remember the name). Kauai revealed was a great resource book that the wife and I used. It tells you all the great things (Restaurants, beaches, and things to do) that you might other wise miss. Here's the link for the guide book:
http://www.wizardpub.com/kauai/kauai.html