http://playaguitarforfree.com/category/guitar-
music-notes/ - Free online guitar lessons.
http://www.largemart.com - This tutorial
teaches how to read music geared toward
piano.
http://www.gmajormusictheory.org -
Download music theory workbooks that teach
fundamentals to conservatory. This site also
includes free sheet music for piano and
guitar.
http://learningviolin.com/eLessons.htm -
Basic lessons on learning the violin.
http://www.violinonline.com - Learn the violin
with lessons on everything from instrument
care and finger placement to online scales,
tuner, technique building exercises, and
much more.