Public Transportation

Prague public transportation (MHD)

Prague has an excellent public transportation system (MHD in Czech). There are trams (streetcars), busses and the metro (subway). They all use the same tickets which can be purchased in the metro stations, the airport, the railway stations, in some newspaper and tobacco shops, some hotels, etc. They cannot be purchased in the tram, bus or subway car - with few exceptions. Follow English instructions on the ticket. Please make sure you validate your ticket as you enter the metro station or tram. These yellow machines are located on posts as you enter. An invalidated ticket is the same as no ticket and if checked by the metro personnel, there is a large penalty payable on the spot. One enters the metro area, tram or bus without having his/her ticket checked, however, the MHD personnell do routine checks often!

The official website for the Prague Public transportation is  MHD is the abbreviation for "městská hromadná doprava" - ie public transport in the city.  

Below is the subway/Metro and tram map.

An airport connection via subway is in the works but until it is completed, this is how you can get from the Vaclav Havel Prague airport to the city center via public transport:
Coming out of customs at Prague Vaclav Havel airport, in the arrival hall, look for the booth/counter with "Public Transportation".  Purchase your tickets there.  They will also have the currect prices and directions to your final destination as well as maps. 
If you don't have Czech money, there are ATMs/bankmachines in the arrival halls also.
March 2019
CZK 24 ticket is good for 30 minutes of travel with transfers. (about 1 EUR)
CZK 32 ticket is good for 90 minutes of travel with transfers. (about 1.50 EUR)
CZK 110 ticket is good for 24 hours of travel with transfers. (about 5 EUR)
It takes about 40 minutes to get to the center from the Prague airport so the CZK 32 ticket is needed.
There are several busses leaving the airport that will take you to the nearest Metro stop.  Bus #100 takes you to Zlicin and from there you take the Metro into the city center.  Bus #119 takes you to Nadraží Veleslavín and Metro from there.  Best to check with the Public Transportation information booth at the airport for all options.