Redd is right. For the most part, you can get away in 99.9% of the planes in AH by flying with Combat Trim on and not need to worry about trimming your plane. Teaching the new player the basic foundation of BFM, ACM and the practical concept of SA is far more productive and will yield tangible results far sooner and will probably also help retain the new player. Knowing how to trim your plane is useless if you don't know how to fight.
ack-ack