An interesting site from Canon about different settings to take Good pictures.

http://www.canonoutsideofauto.ca/learn/

Basic Manual settings for cool visual effects.

A Little About Exposure: Exposure is the amount of light a digital camera’s sensor captures when a photo is taken. Too much light results in a washed out photo (overexposed). Too little light and the photo will be too dark (underexposed). A camera’s Aperture, Shutter Speed and ISO settings directly affect exposure, but more importantly, they allow you to control how each photo will look.