5 links
A.D.A.M. Music School
adam2-1.com
Offers free online music lessons for beginners. Registration required.
Elements of Music Notation
lessontutor.com
Basic introduction to reading music. Learn note names, clefs, staff, and signs. Worksheets with answer keys included.
Guitar Chords
netrover.com
Offers an interactive demonstration of various guitar chords. [Requires Java]
Introduction to Reading Music
datadragon.com
Uses simple terms to introduce the most important topics in reading music.