In London, the metro system is referred to as “the Underground”, or “the Tube”. If you’ve never been to London, you’ll definitely want to have a map of the Underground with you at all times, unless of course you plan on walking or taking the bus everywhere. However, the Tube is a very quick and easy means of transportation, and for the most part it’s pretty safe, so I’d recommend using it as your main means of transportation to places that are too far to walk.
You can easily get a map at any tourist information stand throughout the city, or at your hostel or hotel. Just keep in mind that every time you whip out that map to read it (squinting your eyes, your nose an inch away from the map) you’re going to scream “TOURIST!”. That all fine and dandy if that doesn’t bother you, except for the fact that you might have just become a target for theft, so don’t be surprised when your wallet, or camera, or even your purse somehow magically disappears while on the Tube.
A more discrete, and safer way to read the underground map is to download one onto your iphone, ipod, or smartphone. There are many that are free, and many that cost a few bucks (usd). Just find one that works for you. Once it’s installed, all you need to do is open it, and zoom in whenever you need to figure out which line to take, or which stop to get on/off at. That simple. You’ll blend in a little better, and hopefully won’t be such an obvious target.
Another tip is to buy 0r download the app and study the Underground Map before you arrive in London. You’ll have plenty of time on the plane or train ride there to study the map for 5 minutes or so, and get an understanding of their system. It’ll make a world of difference when trying to follow the directions to your hostel, since you’ll know which tube line they’re referring to.