A few years ago, when I first started talking about sending doctors to Cuba, people questioned the legality of our trips. These last few months of news about re-establishing relations ith Cuba, people are assuming that they will be free to book a trip on their own - if they want to.
Although the American Embassy is due to open in Havana in a few days, August 14, 2015, general tourism for Americans is still a bad word and restricted as long as the Embargo is still in effect. Although there is talk about easing restrictions, your visit still needs to fall into an Educational, Scientific, Culltural, or Religious, People-2-People catagory.
Marimar Travel & Tours has been a U.S. Dept. of Treasury approved Travel Service Provider to Cuba for almost 16 years. They handle all the paperwork and planning.
You need to know that there are NO TRAVEL AGENCIES hawking you to take tours in Havana, like in most other countries. Let me give you an example - this couple from Wales, visiting Cuba for the first time. Their trip included 4 days at the Capri, where I was staying, and 3 at a new Tourist hotel in Varadero. That's it. Their holiday didn't include any tours, so they hadn't a clew on where to shop or where to eat. They just stayed around the hotel pool and complained about how poor the neighborhood seemed to a Brit - although it's considered upscale by Cuban standards...
They weren't traveling with a group, didn't do any research, and since they didn't speak the language, they were having a "faiure to communicate." However, because the husband was pretty sick when he arrived Havana with the flu, now has a story to tell about the doctor and nurse that came to the hotel to take care of him - for FREE!
When you visit Cuba for the first time, my advice is to go with a group, get the lay of the land and experience the Cuban people, which is where the magic lies.