You can expect the same species in HH as in FL. Fish as you would up here. HH has everything you will need, although it MAY be more expensive due to he cost of living there.
You can find head boats, charters and even kayak rentals. They offer kayak tours too. Best bet would be to hit the fancy strip mall on the main drag before you get to the hotel. You can go to the Walgreen's there and find lots of brochures. The airport also has a rack of stuff, go to the old terminal, it's the first one you come to.
Here are some links:
http://www.hhisleinfo.com/what%20to%20do.htm
HH is a very nice place and laid back. I strongly recommend you do the speed limit and watch our for seniors crossing the roads. Walking is a prime means of getting around on the island, especially near the shopping center. Oh, last time I was there, they didn't have stop signs on all of the streets, residents didn't like the things I guess.
Just lay back and take your time.