Taxis are always available from the taxi ranks in front of all the terminal buildings. A taxi ride from the airport to downtown Havana takes approximately 20-30 minutes and the cost is around 30 cuc. Always agree the fare first, some taxis have meters but they are rarely switched on.
There's no public bus (viazul or other) service to/from the International Terminal (3). You'll find a VIAZUL bus station in the *Vedado distric*t of Havana, approximately 15 km from the airport. Viazul has a kiosk in the Arrivals Hall where you can buy tickets but you then have to get to the bus station by taxi. Local buses are available at Terminal 1 (Domestic Terminal) but payment is required in Cuban National Pesos (CUP), not in CUC (convertible pesos), which makes them more difficult for visitors to use.
All car rental agencies are located in the Arrivals area or outside parking.
(Booking in advance is recommended, especially during the high season when the demand for rental cars often exceeds the supply.)