Cycling specific shoes can help in a variety of ways,the stiff sole transfers power more efficiently to the bike, and the ability to attach a cleat and lock into the pedal enhances this further by maintaining the optimal position on the pedal. Being locked in also allows lifting of the pedal to greatly improve power and therefore speed. Overshoes come into their own in the winter or on rainy days, they reduce the windchill or totally waterproof your feet depending on the type. Cheaper than buying a full winter shoe. Expect to them to wear out if you do a lot of walking in them though! Socks - You can buy a waterproof sock or regular synthetic ones to keep you comfortable on warm and cold days.