Whereas telephoto lenses are used to capture small subjects at a distance, wide angle lenses let the photographer include all the detail of a large scene. This makes these lenses particularly suitable to landscape photography and for taking a photo where there is limited space, e.g. a family group in a restaurant. A wide angle zoom lens may have focal lengths ranging anywhere from 12mm to 35mm. Moderately wide angle zoom lenses e.g. 18-55mm are a reasonable buy as a first lens. They are often sold as a kit with a DSLR camera.
Wide angle lenses make the foreground subject loom large in the viewfinder if it's very close. Further from you and it appears to rush away, leaving a blank, uninteresting area at the bottom of the image. You need some strong foreground interest, e.g. an open gate. The change in scale from foreground to background helps to generate a sense of perspective.
These lenses capture a wide view incorporating additional elements all around the edge of the image. Skies can look particularly striking. A polariser filter will add contrast and punch to the clouds, and deepen the blue of the sky.
Ultra wide angle lenses with a minimum focal length of less than 24mm include a lot within the frame but they can also distort the image. The vertical edges may converge at the top and bottom producing a slight barrel-like shape to the image. This effect is less noticeable if you avoid vertical lines near the edge, or it can be exaggerated for artistic effect.
Unlike telephoto lenses, wide angle lenses are not ideal for producing a narrow depth of field, so in most cases your image will appear sharp throughout the frame. You won't be able to make your main subject stand out by softening the background, buy you can achieve the same effect by choosing contrasting colours, such as a red pillar box against a black background.
Wide angle lenses typically have a short focal length. This make them less prone to camera shake than telephoto lenses. See the technique for avoiding camera shake described in the Prime lenses tutorial on this website next month.
Caring for your lens is simple. Protect it in a robust camera bag. Clean the plastic parts with a damp cloth and clean the viewfinder and the front and rear glass elements with a blower brush, and then a micro fibre cloth. Protect the front element by using a UV filter and cover your rear element with a cap when not in use.