Here's the way I was taught to shoot lightening. Set you camera to its highest aperture (f22), your shutterspeed to its longest setting (6 or more seconds), take a lot of photographs. Use a tripod with a cable or electronic release to get the least amount of shake. Aim towards the oncoming storm and keep shooting. Its a lot of luck to get a good lightening photo. Please remember to get indoors or away from the hill your sitting on before the storm arives. Lightening just loves metal tripods and the people with them.

This also works with fireworks, except you try to time your shutter just before it goes off. The high f-stop will give the photo more of the color of the firework. At a wide open f-stop (f3.5 to 5.6) you'll usually get a golden or white color only.