Here's a humorous 2.5 minute video on how NOT to lead games from a youth ministry website called "The Source For Youth Ministry."
The Seven Sins Of Leading A Game:
-Tell the crowd you're going to play a game.
-Forget your props.
-Have leaders watch while kids play.
-Take more than 30 secs to explain game.
-Take more than 30 secs to divide up teams.
-Don't be excited about the game.
-Make sure the crowd can't see the game.