The 123 of digital imaging covers all aspects of digital photography from selecting a camera, understanding the settings, to enhancing, storing, sharing, and printing your images.
Vincent Bockaert has created an excellent interactive tutorial for beginner and more experienced shutterbugs alike. Through an intuitive straightforward interface (best viewed on a 1024x768 pixels or larger monitor) you are guided through starter, essential and advanced sections on all thinkable facets of digital imaging. The guide is well structured; topics are clearly written and exemplified with comprehensive and animated illustrations.
Convince yourself and download the demo version here...