measuring motor current

I need someone to tell me exactly how to measure dynamic current
rise in a step motor using an oscilloscope. Do I put like a 1/10th OHM
resistor in series with one of the coils and measure the voltage across
it? How is this related to the current?
The Bridgeport maintenance manual has scope pictures of current in
the motor windings at different speeds. I would like to be able to
measure mine and compare.
I only know enough about electricity to be dangerous, so please dumb
down your explanations.