That controller has opto-isolators on its inputs, wire the (-) connections to Arduino ground and the (+) ones to relevant pins - the controller needs a few mA and 3.5 to 8.6V so it'll work fine at 5V.
Thanks.
So what will the arduino output be for the positive clock?
is the clock what tells the motor how far to go? can I use the stepper library with this motor/driver combo?