The best thing to do is to lie on the beach and relax. Everything is included and you don't have to worry about anything. Besides all you can eat and drink, also included are bikes, a 20-minute horse ride, and non-motorized water sports. We took a bike ride in the area outside our resort that was exciting. We also went kayaking one day and got to see a beautiful view of our hotel and beach from the ocean.
Quick Tips:
Go on the Outback Safari tour -- it's per person but worth every penny. You haven't really seen the Dominican Republic if you don't.
Bring some Imodium with you. A lot of people got sick from the food. Just be careful and remember it's different than what you are used to. Also, you can't drink the water there, but bottled water is plentiful.
Best Way To Get Around:
The best way to get around is by using the bikes that are included, or just walking. If you want to go far I would take a taxi. I wouldn't rent a car here; the roads and the drivers are terrible!
The hotel is on a 24-mile stretch of beach. We walked about four miles one way and only saw two other hotels. It was a very scenic activity.