It can be very hard to find your way around in London if you do not have a map. But, such a large city can sometimes be hard to cover on a map, especially on a typical image file on the computer, so there we recommend the usage of an interactive map before arrival to London. Most hotels have London maps available, so you should ask for that upon arrival. The metro in London can also be a mess if you are new to it, but once you have the metro map in your hands, everything works out easy and you will get to your final destination with no problem (hopefully).
London Metro Map
London City Map