when he pulls YOU DO NOT MOVE, you dont walk forward, your dog needs your permission to move, he cant make the decisions, i have just taught my newfie not to pull and now hes amazing,
you want the dog to stay at your side no matter what, so as long as hes not walking on a short leash then you stand inplace, you do not move eventually after a while he will turn around and come back to you, when he dose, resume your walk if he rushes ahead again, STOP, like i said he hes pulling no one is to move, it will take a few weeks but after a while he will be walking with a loose leash at your side,
=)