Well, the point is to not put all the weight on the neck, and to roll as quickly as possible at the same time. The palm of your right hand should not touch the ground, form your hand like a half circle, also place your entire arm like half circle. The point is to put the weight on the arm, and then push the weight over to your shoulder. That's for forwards roll anyway, I don't know any good techniques for sideways and backways. Learned it from a friend who does Tae Kwon Do.