What are some good sources to help a youth football coach?
Videos?
Books?
Coach clinics?

Here's a few sites.
http://eteamz.active.com/football/instru...
http://www.touchdownskills.com/tips.html
http://www.knowledgehound.com/topics/foo...
http://www.football-plays.com/
http://www.winningyouthfootball.com/blog...

Those are excellent tools, but the best thing to have is experience and a love of the game and the willingness and ability to communicate that to young people.