One very important thing to know about the Czech Republic, and Prague in Particular, is that the public transport system is superlative. The metro runs from early until about midnight and the trains really do arrive every three minutes during the day. The tram system takes in most of Prague, including the outskirts, and the buses take over where the other services don't go. Finally, all the transport systems are very cheap, (even the taxis, if you are charged the correct amount).