Shutting off your outside tap is very important as the cold in the off season could cause the pipe to burst which could potentially cause thousands in damage. Shutting off the outside tap is a fairly easy project and can be done by hand.
Inside your house parallel to where your outside tap is there should be a valve, shut it off. On the valve you should see a small piece of metal sticking out called a bleeder, loosen off the bleeder and some water should come out.
Finally go outside and open your hose to drain the remainder and leave the valve open for the season.