I can recommend a great Casa in Havana - in Vedado - near the Necropolis.
I also used the services of jorgeguide2004@gmail.com to arrange a taxi from Havana Airport to Jibacoa two weeks ago ... he is real and reliable.
I have to say, from my perspective, the 'scam' issues above seem overblown. It just doesn't sync with my experience in Cuba. If you stop and listen to every story on the street, every tout asking where you are from, and so on, it will wear on you. If you select how and when you will reach out and help individuals etc., it will go fine. Remember, we still live in the top few % of the world's 'rich'. It makes us easy targets. Keep your wits about you, manage your guilt about your good fortune in life so that you reach out and help those in need - not just the loudest touts on the street.
From what I see above, you may want to do Viazul between major centres, and rent a car in some of the places like Trinidad. I also believe the 'fear' around rental cars in Cuba is overblown, but there are risks with it quite different than in most western countries. Just be prepared to pick up hitchhikers between centres when they wave you down. Rental cars have red license plates and a 'T' in front of the numbers, so most locals give up hope when they see one. We put more than one smile on a face - and I got someone to entertain my kids! (Here is 3 mins of my driving video about 25 mins east of Varadero - note the vehicle types on the road ....)
http://vimeo.com/17441488
One place I would like to spend more time in is Sanctu Spiritus ..... but I need something to aspire to for next time ..... enjoy your trip. keep an open and flexible mind.
