A lot of people who get their hands around a camera don't usually bother with white balance settings. But what a difference these settings can make on a photo. Here's a quick rundown to help you get a better understanding of these special lighting settings.
Getting to the white balance function on pocket and digital SLRs can be different. Usually, on a pocket camera, it's found wherever all the preset functions are listed (perhaps under AWB), and on SLRs, there is sometimes a button that says "WB." This can, of course, vary by model and manufacturer.
Auto White Balance (AWB): By default, DSLRs and point-and-shoots alike are set to this setting. Based on the surroundings, natural light, aperture settings, etc., the camera calculates and sets the white balance based on all the contributing focus spots combined automatically. Pretty straight forward.
Daylight: If it's especially bright out and you'd like to add some warmth to your photo, Daylight adds touches of warm tones (usually in a more bluish nature) to your frame.
Cloudy: Like Daylight, cloudy settings tend to be plain and whitewashed under AWB. Using this function you can add some additional warmth (usually a more golden touch) and depth to your photo. Cloudy also works well for indoor photos that are lackluster and need a bit of a natural boost.
Shade: This also adds warm, yellow tones to a photo, but its to combat the natural blue tones often found in the shade.
Tungsten: If there is too much warmth (and perhaps a lot of yellow tones when shooting indoors), you can reduce this with Tungsten, which adds cooler tones, enhances white shades and generally makes photos a whole lot brighter.
Fluorescent: Fluorescent adds warm tones as well, but there usually a bit more red or purple. It could be fun to use for parties, or if there happens to be a lot of red tones in your setting but your camera isn't capturing them very well.
Flash: A camera's built-in flash tends to produce a lot of cool tones on its own, so to combat it, partner your flash with the flash white balance setting to bring in some warm hues and produce a more balanced photo.
Custom: This one might take awhile to be able to master, but basically you point the camera at your target option, and that becomes the neutral object of the frame, with all of the tones based on this single object. It's quite like Auto (and Auto might turn out to be better). But according to Ken Rockwell, you might be able to trick your camera into displaying opposite colors by pointing it at a colored piece of paper or filter (i.e.) blue). Then with the camera set to that photo, press the shutter pointed on your real subject, and the tones should be the opposite (i.e. yellow).
[Key for photos above, from left to right: AWB, Tungsten, Fluorescent]
[Icon image via Adobe]