How to move in London

Althought there's lots of ways to go around London city the best way is definitely the underground.
With the "travelcard" for zones 1 and 2 (where all the action happens) you can use the underground in both zones, all the buses with no zone limit and the DLR (a transport similar to the train that goes around all the London docklands) and you can even get a 1/3 discount on the river boats down on the Thames River. The travelcard allows you to have an unlimited number of rides on the transports.
The London Underground is very practical, secure, clean and is the fastest way to travel around the city (there's a metro in every 1 to 2 minutes).
There's the 1day, 3 day and 7days travelcards that you can by online or when you arrive at London in any station.
The bravest, can go around the city by car but be careful with madness that is the London traffic and don't forget to pay the congestion charge. You can also rent online in the "Sixt" rent a car webpage, a Smart car for only 5 £ per day.