Game Prep and Friday nights?

What are their favorite formations and what plays do they run out of the various formations?
How do they block their run and pass plays? How will this look against our defense and what particular things will be have to do to stop a given play?
What are their tendencies for a certain down and distance, for running to the wide and short side, for running to the TE, etc.?
Who are their best and worst players? How can we match up with their best players and what mismatches can we create for us?
I like to draw up each play they run vs our defense (as close as I can tell). I will have separate sheets for each formation (pro formation plays, twins, formations plays, double tight plays, 1 back, etc). This helps me get a feel for what they are trying to do, and also helps me be sure I am covering everything possible.