With a decent digital camera and a bit of practice, anyone can take acceptable quality photos with the camera set on full automatic. You can even take a bunch of so-so pictures and make them look acceptable later with image editing. But to really wring every ounce of ability out of your camera and produce truly beautiful photographs, you'll need to learn a few things about the manual settings. Keep in mind that lower-end cameras might not have manually adjustable settings.
When you're changing the settings on a camera, you're trying to find the proper exposure for the subject and lighting conditions. Exposure is the amount of light hitting the camera's sensor when you take a photo. Generally, you will want the exposure set so that the image captured by the camera's sensor closely matches what you see with your eyes. The camera tries to accomplish this when it's on full automatic mode, but the camera is easily fooled and a little slow, which is why manual settings usually produce better pictures.
As you get more familiar with your camera, you can play with different exposures for different effects. There are times when auto is better - something happens suddenly and you only have a few seconds to get your photo. Just flip to auto and take a picture. Getting the shot with a slightly incorrect white balance and poor field depth is better than standing there fiddling with f-stop settings while Bigfoot strolls back into the forest.
To adjust exposure, you can tweak two different settings: aperture and shutter speed. Aperture is the diameter of the lens opening - a wider aperture means more light gets through. Aperture is measured in f-stops. Higher f-stop numbers mean a smaller aperture. The aperture setting also affects depth of field, the amount of the photograph that is in focus. Smaller apertures (higher f-stops) give longer depth of field. A person in the foreground and the cars 20 feet behind her could all be in focus with a small enough aperture. A larger aperture results in a shallow depth of field, which you normally use for close-up shots and portraits. On the next page, we'll take a closer look at shutter speed.