Many people think that spicy chilli pepper plants are annums and as winter sets in they will die off, leaving you having to wait until spring comes before you can plant next years chilli seeds.
However the truth is that most varieties of chilli plants are perennials and if looked after will survive the winter, giving you a great head start on next years chilli growing season. One of the key benefits to taking your plants over the winter is that when spring arrives next year you will have a fully mature plant as opposed to freshly planted seeds, meaning you will have ripe chilli pods far earlier. In addition most pepper plants will fruit much more heavily in their second or third years than in their first. For hard to grow varieties that take longer to fruit such as habanero this can make a huge difference.
The first thing to do to over winter your chillies is to give them a certain haircut, doing so will mean that the plant does not waste any energy maintaining its foliage. Keep the plant inside, ideally in a greenhouse or a conservatory and it will in effect go into hibernation. You should ensure you water the plant often enough to stop it drying out, but not too much.
For a few months the plant will look dead but persevere and with a little bit of luck once the temperature and light levels rise in the spring your chilli plant should come back stronger than ever.