Charged particles are thrown off by the sun and can intersect with the Earth's magnetic field. These particles can be drawn down to the magnetic poles. Being so energetic, they cause molecules in our atmosphere to glow like a neon sign - this is the aurora
The perfect site is nice and dark, and has a good unobstructed view of the southern sky. A dark site will preserve your night vision and make photography easier too. Your view south should have no artificial lighting.
In reality most of us have to contend with light pollution in one form or another. As much as possible you want to minimise artificial lighting to the south south. You also want to avoid bright lights shining onto your eyes and camera.
Depending on the brightness of the display, it can range from smokey white, to vivid greens, reds, and purples. It can hug the southern horizon as a minor display or swirl overhead in a major storm.
For most people there is the impression of a ghostly green glow in the sky. This impression can be intensified when it shines through a hole in the clouds
Some tips to maximise your chances of seeing the aurora include:
More questions and answers to follow soon, especially how to use this site!