Open up your manual and see how to adjust your shutter speed.
Set your camera on M for manual mode. You can shoot anywhere from 1 sec to 25 seconds at night depending on how dark it is outside. Bulb mode works great as well, it holds the shutter open until your press the button again.
For lightening, I use the camera in bulb mode set around Fstop 9 or so. Keep the shutter open until lightening strikes, then you close it. Normally takes a few shots before you get a worthy photo.