All of the above is true. Havana is an amzing place to visit (old Havana that is). The cubans we met were wonderful, warm friendly people but very poor. We took some simple presents for hotel workers, gardeners etc we met such as toiletries, kids toys (colouring books, crayons and the like) as these things are hard to come by in Cuba. You'll be surprised by how happy they are.
A visit to the Havana Club Rum factory was good, with free tasting at the end!
The main thing I can suggest is to go there with an open mind. Forget about the communism, lack of wealth etc and just soak up the music, atmosphere and the rum! It's a wonderful, totally unique country with equally wonderful, unique people.