1990 Mercury Sable disc brake caliper

After my brakes are applied, sometimes I can feel the brakes still dragging. I sometimes place the trannie in neutral when approaching a red light and I quickly come to a stop without any further application of the brakes. Upon acceleration sometimes the car begins to shake rather violently until ( I think ) the caliper releases and the rotor cools. I am assuming the wobble and shake is caused by the rotor warping and then after cooling( and the caliper slowly releases ) the wobble stops. After I stop the vehicle I can get out and feel heat radiating off the front brakes as well as at times see faint smoke. How or what do I need to do to stop this "sticking" of the front calipers, IF that is the problem? Thank you