Getting to Havana from the Airport
Since there is no public bus service to or from the international airport, the traveller’s only options are privately arranged transportation or a taxi.
Taxis can be found just outside arrivals, on the ground floor exit. A taxi to Central Havana should cost between 15-30 CUC.
Do not forget to reconfirm your departure flight, especially if you are flying with Cubana.
Even if your flight has been reconfirmed, overbooking may happen and you may still be denied to board the flight. You should try to arrive at the airport as early as possible (at least 3 hours prior to the departure), and ask for a confirmation reference when reconfirming any flights.
Before May 1, 2015, every traveller had to pay a Departure tax of 25 CUC when leaving Cuba. Now the Cuban Departure Tax will no longer be paid at destination. It should be included in the price of your trip when buying a flight-only or package to Cuba.
(source: http://havana.airportcuba.net/tax.html )