TAKING A PICTURE:
You generally will not be able to take good pictures of the Northern Lights with short exposure times. Good exposure times for this are 20-40 seconds per picture (the tripod will help you eliminate shaking of the camera - you can't hold the camera by hand.) Now, this can be adjusted depending on the brightness of the lights, the aperture you are using and the ISO you set your digital camera to.
I have taken photos of the northern lights with ISO as high as 6400, with apertures as much as 1.4 and shutter speeds that range from 3 seconds to 15 seconds.
A sample exposure time for ISO 800 with an aperture of f/2.8 would be 10 to 20 seconds depending on the brightness of the lights.
LOCATIONS & TIMES:
It can be hard to predict the Northern Lights so you may be in for a few hours of waiting during a cold night.
The best times generally are after midnight and range from October to the end of April each year. In Canada, the two best places I have found are near Yellowknife and near Whitehorse.
3.Include a part of the landscape to make the photos more attractive and as a visual reference for size.
4.Do not use any filters, as they tend to distort the beauty of the Northern Lights and degrade the image.
5.Turn on "noise reduction" and the white balance can be set between 3200K to 5000K or set to auto on digital cameras.