Been going to Anna Maria Island every year since 2007.
There are three towns on Anna Maria Island. We always stay in the City of Anna Maria, so I can't speak about the other two.
The scene is very laid back...we spend the majority of our time at the beach.
There are some decent restaurants. The Waterfront is near the Anna Maria Pier. Slim's is on Gulf Drive, and though it's a bit of a bar/dive, has some excellent lobster mac/cheese. Poppo's Taqueria on Pine Avenue is a decent lunch venue. Island Ocean Star at Galati's Marina has some excellent sushi. Finally, the restaurant at the Waterline Villas and Marina is just about as good as it gets on the Island.
Of course, there are some tourist traps. The Ugly Grouper is always packed and the food is so so. Rod & Reel is located over Tampa Bay. Been there for years. Kind of dumpy but it's neat to be over the water looking at Tampa Bay.
Finish the evening with some ice cream at Two Scoops, located near the Anna Maria Pier.