My basic route:
Take a car, otherwise getting around will be a problem. Dont use hotels, they are garbage.
1 Day in bay of pigs, good beach and casas on the beach
1 Day in ceinfuegos, good to party on weekends
Drive thru Trinidad, if seel then go to La Boca beach for a Case
1 Day in Sancti spirius, a good inland town
Drive thru Santa clara, see the Che memorial
3-4 Days in havana for sights and stuff.