You will want layers. Good base layers like underarmour and merino wool. merino wool socks. When I is real cold out I double layer socks with a thinner bicycling under a thick wool sock. Good gloves and glove liners. Waterproof, breathable shells and make sure they have zip vents in the jacket. As El Sid mentioned, get breathable material, don't use cotton in your base layers. You need the base layer to wick the sweat away and adjustable vents to give it somewhere to go.