It's pretty simple really. Most old-school light meters use a dial type setup which is quick to understand. First you set your ISO/ASA to the speed of the film you are using in your camera, then you aim the meter at the subject. On the needle scale, there will be a series of lines (often silver and black), you turn a marker on the meter until it matches the line where the needle is pointing. Then look at the corresponding shutter and f-stop settings, you can use any of these settings depending on the effect you want, faster speeds with wider apertures, or slower speeds with narrower apertures.