Well the only things you really need to wear that are biking specific might be your padded shorts, helmet, and bike gloves (to protect your palms in a skid-out on asphalt). Aside from that you can layer on regular warm stuff like sweat pants, turtleneck, over-gloves, warm socks, etc. Keep in mind that you don't really need to be in 'official' biking clothes just to ride your bike, unless you need padded shorts for a long ride. Have some fun with funky-chic layering!