The are things that make you get out of your tent at night and walk under the rain. Usually, I want to be quickly back inside but on the night I'm telling you about a storm on the horizon held me up for almost two hours. When it would intensify I would set a tripod up and try to take a photo of the sky while lightning bolts raged. When I would grow desperate I would prepare to go back to sleep. But then the storm would intensify again so I would go back to trying... and trying... the wrong way.
What I did then was rely on chance. I would set my shutter speed to 30 seconds, start the exposure and hope that before 30 seconds would pass, a nice bolt would cross my frame. And eventually it did - the one you see above. But had I known a better way to do it I would have captured many more and earlier.
So after I got home I decided to read about how it should be done. Ah, so that's what that Bulb setting means!
On a good camera you have the option to set your shutter speed to Bulb. It is immediately after your longest exposure, for instance 30 seconds. The way it works is... You press the trigger and hold it. The shutter will remain open until you release it. You should better use a remote control - cable or wireless - to avoid shaking your camera. It is also much less awkward if you don't have to be crouching at your camera for a minute or more.
So that way you can make exposures longer than 30 seconds, even minutes. Or more! Just be sure you have enough battery charge. The trick is to release the trigger and thus - the shutter - after you see your lightning, or shooting star, or whatever you hunt for.
A lot of times it will be in less that 30 seconds. Yes, the exposure can be long, but not necessarily. You should be prepared for that, though. There's a catch. Sometimes your bolt will come before the image is well exposed and sometimes, especially if you shoot during daylight time (A.K.A. day) the image will get overexposed before you see the thing you hope for.
In the first case, well, if you experiment a bit you will know how much you have to hold to get enough light and you can wait for a bit longer after the lightning (let's call it that for short) crossed your frame.
But in any case, if you expect to wait for long seconds, minutes, etc., be sure to have set your other settings to minimum exposure. Lowest possible ISO and a well closed aperture - the latter depending on your choice, eventually.
And what remains is to be patient.
Good luck and have fun!