Cuba Education Tours provides knowledgeable and ethical approaches to Cuban Tourism. Read Green Cuba Resources on their website and book a tour or just find out more about Cuban tourism before you go.
You may also want to keep an eye open for David Suzuki's documetary Cuba: The Accidental Revolution that examines Cuba's success in providing for itself in the face of a massive economic crisis, and how its latest revolutions -- an agricultural revolution and a revolution in science and medicine -- are having repercussions around the world.
"Anyone interested in ecologically sustainable development...will find this documentary thought provoking." Gregory Biniowsky, Canadian Development and the Environment Consultant living in Cuba.