Muskyhunter gave a very good tip. Don't forget to buy pencils, tee-shirts, toothbrushes ... before leaving for Cuba. Most of the people there are very poor and they will sure appreciate a little help.
For a photographer Cuba is a little paradise. Beautiful landscapes everywhere on the island, marvelous cities (especially the Old-Havana, Trinidad, Santiago de Cuba) and friendly people that usually love to be taken in photos.
If you can, try to rent a car. Driving is easy and you won't have to bother about the lack of public transportation. Try also to avoid the hotels, that aren't top-notch and are all under control of the army, prefer to go in some Casa Particular. Some of them are located in beautiful old spanish palaces and you also will have the opportunity to talk with your cuban host and receive very good advices about the place.