I was in Cuba in November 2006, drove just about the entire length of the country in a bit over two weeks.
It's quite safe, although there are lots of touts. As others have said, always watch your belongings. People are incredibly friendly and you'll have no problems taking candids. On occasion, you might get asked for money, esp by a tout. It helps if you can speak Spanish -- not everyone speaks English (I'm a native Spanish speaker).
Old Havana is beautiful, but definitely get out into the countryside -- there is so much to shoot there, it's a photographer's dream. Even in the harshest, noon-day light, you will get amazing photographs. Among the places we visited that I would consider must-sees: Trinidad, Baracoa, Vinales, Pinar del Rio, Santiago. Also some small villages whose names I don't recall offhand, but can try to get for you.
If you're driving, be careful. Some of the roads are pretty bad, esp the farther you get from Havana, and the signage can be TERRIBLE! A lot of people hitchhike, and it's a great way to meet people, but if you don't know your way around, this might not be such a good idea.
As Harold Clark said, take soap, good used clothing, cosmetics, but also pens and pencils and note pads and small notebooks. My companion and I took old clothes and just gave them away as we travelled, so we had lots of room for souvenirs.
Oh, and it's not cheap either. We rented a car -- both manual and auto transmission are available, but the auto costs an extra US$20+ a day. For food, check out the paladares; the food in "official" restaurants is generally pretty awful. Also, definitely stay in the "casas particulares" -- decent accomodations with breakfast and lots of Cuban coffee (I was in heaven!); plus you'll get to really connect with people. All told we spent close to US$80 (per person) a day -- that was for room (around $22 each), food ($20.00 each), gas (expensive!) and car rental/insurance (around $75 daily) -- but not including all the souvenirs we bought: cigars, rum, artwork, etc.
If you book the Havana hotels in advance (on the Internet), it's about half the price by the way. We made the mistake of booking our first weekend on the web, but not the last, and ended up paying double the original rate. Again, I can't remember the name of the hotels in Old Havana, but can dig them up if you like -- worth the splurge
Some basic info at
http://wikitravel.org/en/CubaIf you want any more specific advice, contact me directly. I've also got pictures, check out
http://www.flickr.com/photos/madame_suzuki...57594382323487/aa