balaclava or lightweight cap for light cold, a windproof (not cycling specific) jacket with a hood. what to wear under jacket is easy to figure out. i have a pair of leather garden gloves for cold, thick insulated gloves for colder, and 3 fingered cycling glove ($20Amz) for coldest. For feet i have neoprene toewarmers and then neoprene overshoes for pretty cold. long biking pants with long underwear for coldest.
a lot of it depends on if it's sunny or not and how windy it is. going to be 32F here when i ride at first light tomorrow, so i'll get a chance to try out winter uniform.