I can't say this for sure, because I haven't looked at dryer motor windings extensively, but I'd say it grounds through the body's mounting bolts, then has on output that's a centrifugal switch (to activate the heater circuit, or rather disable the heater circuit if the motor isn't running) and as for the two wires involved with the capacitor, I'd assume one is neutral and the other is incoming voltage, but when dealing with high voltage AC circuits knowing before testing is very important for safety.
Can you get a diagram for the dyer to see how this motor interacts with the controls? The diagram is usually on a piece of paper inside the control panel area, or on the back of the unit. Often times people don't put it back though.
