Just select the "DC volts" setting on the dial, assuming you've got a multimeter, and connect one test lead (red) to the large output terminal of the alternator, and the other test lead (black) to the alternator housing, the engine block, or any other ground. You can also connect the voltmeter across the battery posts. With the engine off, the meter should show battery voltage, somewhere near 12 volts. If the alternator is charging, the running voltage should be somewhere between 13 and 14.5 volts, depending on the state of charge of the battery. If it's not charging with the jumper installed, you've probably got a bad regulator or worn-out brushes in the alternator.
Jerry