This nifty online tool is a great introduction to the three primary camera settings: ISO, shutter speed, and aperture
If you know your way around a camera, the interplay between ISO, shutter speed, and aperture are probably a second nature to you by now. But for new photographers, the ASM modes of PASM can be tricky to get your head around. Canon has created a new online tool called Outside of Auto, that should help newbie photographers understand the interplay of these three elements, and how to use them to take fantastic photos.