Keep It Simple
This is Pop Warner flag football, not the Orange Bowl. The goal is to learn the fundamentals of the game and have a positive, safe playing experience. There's a tendency, especially among former athletes, to coach beyond appropriate age levels. The flag football playbook should consist of no more than five or six offensive plays and two defensive sets -- and none of them should involve the Statue of Liberty.
Remember, some of these kids have never held a football before. Don't be afraid to start at the very beginning. Before you can even think about learning plays, you need to teach them how to throw, catch and run with the football. Teach them the correct way to throw a spiral. Show them how to catch and cradle a ball before they start to run. Teach them the best way to "tackle" an opponent (take their flag) by staying in front of them and grabbing the flag as they try to pass.
Make sure that each player understands the basic rules of the game. What's the line of scrimmage? What's a first down? How many chances do you have to make a first down? Teach them how to avoid common penalties like offside, holding and blocking the flag.
When it's time to run specific offensive and defensive drills, stick to three running plays, three passing plays and two defensive sets (man-to-man and zone). Run each play in slow motion first. When the offense perfects the play in real time, throw in some defenders.