Wow TNT... just wow. I don't like Soccer, but I wouldn't call it whimpy or any of the other very disrespectful things you just did.
I am living in Peru now, where Soccer is the national sport, but I just can't get into it. At the same time, I am getting some of the locals into the NFL and they are loving it so far.
The first thing I explain is the basic concept of the game, and then answer questions as they arise while not getting too complicated and listing all of the possible exceptions. Instead, I address the exceptions when they arise instead of overwhelming someone... which in my opinion is one of the best ways to teach.
The first thing I explain is that the field is 100 yards long and when a team has the football, they are given 4 tries to gain 10 yards or more. If they are successful, they earn a new set of 4 tries to gain an additional 10 or more yards, but the attempts do not accumulate. If your team fails to gain the needed yards, you forfeit the ball.
Next, I explain there are two ways teams try to move the ball. The first is by running it. The second is by throwing it. Play stops if the person carrying the ball is tackled to the ground or exits the field of play. Play will also stop if they attempt to throw the ball, but nobody is able to catch the pass.
Finally, I explain scoring and kicking. Teams can score one of three ways:
1.) By getting the ball carrier into the end zone for a Touch Down. This is worth 7 points [yes, it is only worth 6, but keep it simple]
2.) By kicking a Field Goal. Kicking the ball between the Large Metal goal posts. This is worth 3 points. This is easier to do than scoring a Touch Down, so kicking two Field Goals isn't as valuable as scoring one Touch Down.
3.) The least common way to score is to push the other team backwards into their own end zone. They are pushed so far back, they have no where else to go. This is worth 2 points and you are awarded the ball.
Once this is understood, we talk about the basic strategy of Punting. After that, questions are asked and answered as we watch a game.