These two turned out OK but have a strange colour to them. Time of day, maybe? I have never tried it but MA should be able to offer some advice since he has a few really nice lightning shots.

Without Googling any details I would suggest a tripod, a remote shutter release, a large F-stop both to block as much light as possible and to increase DOF to the max, and a low ISO 100 or lower if you can get it.

Put the camera on bulb or a very long exposure and let the lightening be your flash.

I've been anxious to try but we don't get that many lightening storms in Halifax.