The Northern Lights
Let's face it, we're here mainly for the Northern Lights. True, we'll see wildlife, fall color, pretty landscapes and all that. But really, it's the auroras we're after.
With that in mind, here are a couple of references to give you a head start of capturing some amazing images. It's always best to come into something that may be new to you with as much preparation as possible.
How to Photograph the Northern Lights
Not only the how-to, but the how-come. What makes the auroras happen and how you can best predict them.
You can get your copy here.
A neat little book on photographing the night sky.
Get your copy here.
Grant Collier's Guide to Night Photography in the Great Outdoors
Really good book that covers a lot, including processing your night images. Read my review here.
And for those with a technical interest, here's the NOAA Aurora page.