Snow & ice riding is the best way to improve balance on your bike. Not to mention it keeps you in shape so when spring comes you don't feel like you're dying on the first ride of the year. Dress warm, but not too warm. You heat up pretty quick. You should be a little cold when you start the ride to accommodate for this. Snow really burns the legs and since you're not moving real quick you can get overheated easily and start sweating a lot. The moisture from the sweat will really make you cold. Wearing light layers is a great idea so you can shed clothing and easily stuff them in your camelbak if you do feel you are over dressed. Studded tires do help on the ice (still not like riding on dry dirt though), but for snow a nice fat tire is the best choice.