[Psycho0124]

If it's a common type of bib, it should be fairly simple to fix. Loosen the nut on the valve that the handle passes through. When you've got it off, the handle and nut should come out of the valve. You will see a flat circular area with a rubber washer and a screw in the center on the shaft opposite the handle. That washer is likely old and crispy/cracked and can be replaced at your local plumbing shop for a few cents (show them what ya got). Be gentle when you take off the screw that holds down the washer as they get pretty brittle and can crack off easily on an old valve. Also while you've got the valve open, take a look down in there. There should be a smooth face that the washer mashes down onto to close the valve. Look for pitting, corrosion, or deep valleys. If it looks like the surface of the moon in there, you might consider investing a few bucks in a new valve some time soon but a new soft rubber washer should keep it from dripping for a while. Reassemble the same way you took it apart. Don't tighten too much as you'll mash the packing inside that nut and it'll leak at the handle when it's on.