The best time for Northern Lights is on a cold, clear night. Go out to the bluff at the airport - or if you are willing to get out of your car and brave the cold for a bit, go up to the Flat Top parking lot!
The northern lights tend to be wiggly lines across the sky made up of lots of downward pointing rays, they move and twist and change thickness sometimes at a rather fast pace. Try imagining a little kid drawing a river, and then lots more rivers around it.
Yes there are. They are the same phenomenon as the Northern Lights. It happens at both the north pole and south pole. The Northern Lights can be seen in much of the northern hemisphere and the Southern Lights in much of the southern hemisphere.
Other than impressing them with their beauty and inspiring them to awe - the northern lights really don't have any effect on people. The solar radiation that causes the northern lights can interfere with radio transmissions so that is an effect related to, but not cause by, the northern lights.
The noun Northern Lights is plural, a word for more than one light. The Northern Lights (also called Aurora Borealis) is made up of a series of many lights. The noun Northern Lights is a proper noun, the name of a specific thing. A proper noun is always capitalized.