Despite the large offer of bike shoes available on the market you may find it pretty difficult to get a pair that matches your expectations. Before going shopping, it is a good idea to search on the web and see what the scores are in special cycling catalogs, the only big problem the may appear with shoes ordered on the Internet is size. If some bike shoes from a certain manufacturer are size 10, they could actually be half a size smaller or larger than others produced by a different company. Or even a clearer example is the huge size difference between European and American bike shoes for instance.
Consequently the best word of advice you can get is to buy some bike shoes that you can actually try on and see how they fit you. One further important aspect you need to look for is the type of sole fittings since they have to adjust well to the pedaling system the cyclist is using. Whether your bike has a Shimano, Campagnolo or some other pedaling specificity, checking with the manufacturer of certain bike shoes on the web becomes a necessity. The bike shoes must be neither too tight nor too loose on the feet: comfortable is the standard; this aspect is all the more important since a lot depends on the type of socks you wear to keep the feet warm.
Instead of regular bike shoes, professional cyclists often turn to thermal booties during the cold season. These should be both warm and waterproof to prevent your feet from getting wet, since humidity is the first step towards not being able to fight cold. Instead of booties, one other option is the use of special waterproof covers that are placed over the bike shoes; such apparel items do not prevent the normal air flow at the feet level, but they don't allow external moisture to get in. If the shoe covers are made of goretex, you won't have to worry about rain, wind or cold in general.
The bike shoes to be used in winter are usually a size larger than normal cycling shoes since they need to go together with thick warm socks. The problem with too tight bike shoes is that they don't leave enough space for a warm air pocket to form between the shoe and the foot; thus, toes can immediately get cold. Another option many cyclists choose is that of using some synthetic liners between the bike shoes and the boots; the choice is yours as long as you manage to ensure an adequate comfort level.