Winter Cycling Tips:

Studded tires make riding a bicycle on ice much safer. The front one insures you won't fall on your face, the rear one helps give you enough traction to move forward.

Full coverage fenders will keep your bike significantly cleaner, which means it corrode far less. And they keep snow/slush/water from flying up at you too.

Cold drains batteries much quicker. Consider getting a dynamo lighting setup so you don't have to rely on batteries.

Your body generates a significant amount of heat while cycling, so it is best to dress so you will be somewhat cold the first mile or two, then you are more likely to be comfortable for the rest of the ride.