Music and You Music and You has some very nice offerings.  It is run by Alana LaGrange in California and has a free orientation that you can try as a sample.  I did try it and was very positively impressed.  There are four free lessons and they start with very basic material which you can access at no charge.  The best thing to do is print them - they look great coming off a color printer.  These are clearly not diagrams that were dashed off in five minutes.  They are sized perfectly for printing and can serve as an introduction to the keyboard for a child or an adult.  Take a look at the orientation at Music and You .  After the free orientation, there are a few demo lessons you can take to get a feel for what the rest of the lessons are like.  In the demo lessons you'll see the same quality of diagram and if you click on the clef symbol at the bottom you can hear the sound samples.  The lessons are offered at three basic levels; beginner, intermediate, and advanced. The beginner lessons are an interesting mix of standard instruction and classical music and pop.  They include sections on reading music, rhythm exercises, finger exercises, and songs that teach music reading skills. There are  forty eight intermediate lessons that cover chords and scale theory, how to play intros and endings, an introduction to jazz techniques, and much more.  The advanced lessons cover additional jazz chord techniques (9ths, 11ths, and 13ths).  There is a section on modal scales and their application and studies of synthetic jazz scales, pentatonic scales, and minor scales. In addition, the new information is applied to a set of songs and the student is given practice sheets explaining fingering, pedaling, phrasing and rhythm.        The site has been up since 1999, and you should read about the author, Alana Lagrange, on the "About Us" page. Take a look at Music and You.  I like the site and the materials a lot.