I have been playing guitar for about a decade. I began by playing chords and quickly moved to tabs. I am quite skilled and have no problem improvising. Recently, I decided to give a try to an acoustic guitar and learn finger picking. This leads me to want to learn sight-reading sheet music.
A long time ago, I started learning to play guitar from sheet music. The book I was using began with a few simple songs that used only a handful of notes. Each song would use more and more notes, providing an opportunity for practice and gradual improvement. Is there similar material available in the public domain? I have been searching for books or tutorials, but what I find seems to focus on specific techniques (strum patterns, chords, scales, etc.) which are of little use to me.
Any links to material or other suggestion would be greatly appreciated.