Getting around a big city that you're not familiar with can be a daunting experience, especially if you're trying to use public transit. But there is a website that can help you find your way. PublicRoutes.com
currently offers directions for seven US cities, most recently adding, Los Angeles to the list. After entering a start and destination point, you can select a mode of transportation, including bus, subway, driving, walking and more. The system generates turn by turn or station by station directions, so you know where to get on, off or change buses or trains.
Alternately, try Google Transit