I grew up in N. Idaho and that's where I learned to drive. I'd say one thing that you may want to do this winter is give yourself extra time when traveling. It will probably take longer to reach your destination in the winter due to inclement weather and roads. That may seem like a "no duh", but since you are used to decent roads most of the year, just keep in mind that it isn't as easy to rush to a meeting or out to grab groceries.
My advice for the actual driving part is much like everyone else's: practice, practice, and reasonable speeds. And I think everyone has covered the basics well, the important ones to me being:
-Snow tires are great
-Emergency kit: things for warmth* and light**
*My parents who still live up N. Idaho always have sleeping bags, gloves and hats in both of their vehicles during the winter months. Granted they live in a more remote area, but better to be warm and cozy no matter where you are. Every winter you hear stories of people getting stuck somewhere.
**Coming from Cali to further north, other than the adjustment to cold and snow, might be how short and dark the days can be during the winter. Make sure to have headlamps, candles, or emergency glow sticks