Tim Gardner was one of Southern Methodist University's star football players.
This series of videos (each about a minute and a half long) explains many of the advanced techniques of football. He covers things like proper reads by the safety, how to properly catch the ball, hold, back pedal, wr route running and other topics. It's a worth watching and I think it helps to better evaluate players.
http://homegarden.expertvillage.com/videos/advanced-football-ball-positioning.htm
Here is a sample of one of the videos
http://www.youtube.com/watch?v=N9ZfjlKxFGM&feature=related