Simple, easy-to-read information and advice from the State is here.
If you do nothing else, wash your hands frequently. Good hand washing involves soap and warm water, and you should spend about 15 seconds lathering up your hands - about as long as it takes to hum the "Happy Birthday" song either out loud or mentally. Rinse, dry off with paper towels, and use the towel turn off the faucet and to open the door of the rest room.
Update 9/22/09: More information from the state here.