First you need to be a decent enough pilot that your clubmates agree that you are capable of helping someone else to learn. Then you need to be willing to be an instructor pilot. Next your club will notify AMA that you are capable and willing, then pay the ten bucks.

There really isn't a certification, instead you will be given a set of guidelines on when a student is covered by your membership and when they should begin membership. You will also recieve an AMA card that identifies you as an instructor pilot and a nifty patch. Your new card will say intro on it.

Vic