Also, you must use hand signals to indicate turns and stops. Just to refresh, here are the hand signals for bike riding (also helpful when your blinker is out):
You don't have to give the signal continuously. Just give the signal at the right moment before your turn, such as when the light changes, or you are moving from a stopped position to start moving again, or if traffic is approaching you from behind.
Remember, you are an ambassador for commuting bikers everywhere, so practice these laws to set a good example. The more cars see good bicyclists on the road practicing the proper biking procedures, the safer everyone will be.