He should know how to yield to the bit before you ever try riding him with it; you can teach him how to bend with the bit from the ground, by simply taking some of the slack out of one rein, and bringing it up to his wither; hold it there until he 'gives' to it, by bringing his face toward his belly. Start out asking for just a bit of bend, and go from there. This way, when you do get on for that first ride, you atleast know he knows the concept of turning in each direction. This will give you the power to be able to teach him a one-rein stop, in which you will take up the slack in one rein, and wait for him to stop, before releasing the pressure; I would also wait from him to 'give' to the pressure before releasing too, so you reinforce 'bending' even more.
"The ideal horseman has the courage of a lion, the patience of a saint, and the hands of a woman..."