Kauai in December!

I am so excited about traveling to Hawaii in EXACTLY one month from today. No, I am not in shape and I am totally white but who cares?! I am going to paradise! I have researched local eats and hiking trails but I am feeling a bit overwhelmed. Loyal readers: What do you recommend? What are your "must do's" while in Kauai? I appreciate any feedback. Ok, off to the treadmill - I have a bikini to look good in...