Find the chain that is located closest to the ceiling fan's blades. If the ceiling fan has a light kit, there will be two chains. The lower chain controls the lights; the top one controls the fan speed. If no light kit is on the fan, there will be only one chain that controls the fan.
Pull the chain once until you feel or hear the switch click. This will start the blades turning and the fan will be on its fastest setting.
Pull the chain a second time, and the fan will slow down. It is now on medium speed.
Pull the chain a third time, and the fan will be on low speed, its slowest available speed.
Pull the chain a fourth time to turn the ceiling fan off.