Everyone starts at the baseline with a ball. When the coach says 'green light', the player starts to dribble and walk. When the coach says 'red light', the player stops.
For the younger kids just learning, tell them this is not a race. When 'red light' is said, let them pick-up their dribble. As the level of play increases, different variations could be things like walking backwards, making it a race, using opposite hands, or any errors in dribbling having the player to go back to start. You can also use a whistle; one blow signifies 'green light' and two whistles mean 'red light'.
This basketball drill is licensed under a Creative Commons License. This drill is from Pål Degerstrøm at www.degerstrom.com/basketball.