One of the cruises we took had lunch on the island which is included in the price. The guide was very informative and pointed out whales, seals, puffins and bears. You can fish from the shore or go out on a day boat. If you take a car drive, you will see moose etc.
Quick Tips:
A good time to go is in June when it is not so busy. The weather is good, but you may need a jacket. You will probably need to reserve early. Best Way To Get Around:
If you fly into Anchorage, you can take a train or rent a car. It is a easy drive and on the way you can stop and may see some glaciers that have broken off.