Michael Totten recently visited Cuba. He has posted a great article at World Affairs Journal on the truth of Che Guevera. We highly recommend reading it - we learned a lot.
Here is his photo of the military fort, La Cabana, that Che turned into a prison. He executed thousands against these walls. It is now a tourist location, but during the revolution it was known as the Caribbean Lubyanka.
Totten recommends Humberto Fontova's book, Exposing the Real Che Guevara, and the movie, Before Night Falls.
UPDATED 2.13.14 9am:
DO NOT buy the movie, Before Night Falls. Great actor, horrible script. It is gay all day, with hints of revolution. I turned it off early, but not early enough.