With the coming of spring and the seasonal change, so comes the opportunities for increased thunderstorm activities. Great and massive clouds roam the skies and on occasion, yes we get that magical storm with all its beauty, mystery and some great lightning. As tempting as it can be to grab the camera and head off to capture some great shots.. Safety under these circumstances is first and foremost. Common sense can go a long way here folks.. never shoot in open fields, under tall trees, or near a water source such as ponds, lakes, etc. Most of us know this already but in the heat of the moment in trying to capture that illusive shot we may tend to ignore and forget this basic survival skill.

Whenever possible you should try and shoot from indoors or under cover of a solid structure. I have even shot from within my vehicle with good results. This is two fold… one – you remain safe, and two – your equipment does not get wet or destroyed in rainy conditions.

The next basic thing is to have reliable and capable equipment for shooting these elusive and temporary storms and events.You do not need a multi hundred dollar camera for capturing these storms.. a simple SLR film, digital  or even a good point and shoot camera is more than enough for creating some great shots.  
Below is a good article I came across:

When it comes to finding the right tips for taking photographs of lightning, you should keep in mind that the most important rules you can follow have nothing to do with photography at all. Rather, they are more for keeping you and your equipment safe. While photographing nature at her wildest is one of the most thrilling challenges photography can provide, there’s little point to it if you end up risking getting electrocuted or drench your best cameras in the process.

The ideal tips for taking photographs of lightning center around what type of storm to follow. Ideally, the type of weather is typically when it’s not raining or hailing and the wind isn’t dangerously high. Other atmospheric conditions include what type of clouds are above. Some storms have clouds where the lightning will arch downward, where others consist of clouds where the lightning appears as brilliant bursts of muted flashes from deep inside the clouds. While both provide wonderful pictures, it’s a good idea to know the difference between the two.
Another good way to ensure that you always take great storm photos is to take a good look at the natural and unnatural sources of light around you. Taking photos of storms on bright, sunny days is one of the most difficult, as there is little contrast between natural daylight and the bolt of lightning itself. Be sure your flash settings are adequate: sometimes the burst of light is too bright, and you end up with the landscape in sharp focus, but a blurry lightning bolt.
Another fun way to create unique storm photos is to make good use out of the landscape around you. Few things are more dramatic than an excellent shot of a firey bolt with a tree or a building standing silhouetted with it. The more you practice, the better you’ll get at discerning what subjects go well with storm photos. For a symmetrical effect, try choosing naturally tall things near the bolt, such as radio towers, cactuses, or spires.
These are only a few tips for photographing lightning to consider. Keep in mind, as you practice, that a lot of photographing unpredictable subjects like these lies in skill, reflexes, and blind luck as well. Don’t be discouraged if it’s not perfect right away. With practice, you’ll learn how to make the perfect shot.