If you are new to winter biking, you may want to ask one of the trained technicians at one of the local bike shops to 'winterize' your bike for you. Let's start out with bike maintenance. The cold and wet weather means that your bike will definitely get soaked on your ride. Any steel surface of your bike has a tendency to corrode, so pay attention to your chain and exposed areas of the frame. Snow, slush and ice wreak havoc on cable systems.
Housings can fill with water and freeze solid.
Your brakes will become immobilized by icepack. As a precaution, you should lubricate the sections of brake cables where they stay in the housing to avoid rust. You will also want to spray your rear cogs and chain with silicone before you go out on an icy ride. This should also be done when you get back home after drying off the bike. You may also be able to adjust the tension on your derailleurs.