The following supplementary pieces are provided to help broaden you skills as a guitarist. Each one presents a different challenge, and will improve both your technique and your fretboard knowledge. The first one is a fingerstyle Blues piece which uses constant bass notes played on each beat with the thumb (P).
This Folk/Country style piece can be played with either a pick or the right hand fingers. Once again, take your time, and be sure all the notes sound clearly, but damp out any extra unwanted notes, with either the right or left hand.
Here is a Classical Sonata by Italian composer Domenico Scarlatti. This piece was originally written for harpsichord, but also sounds great on the guitar. It will test your note knowledge, as there is no tablature. Once you can read traditional notation well, a whole world of music written for other instruments becomes available to you.
To finish off, here is a piece written by one of the greatest composers of all time – Johann Sebastian Bach. This prelude was originally written for the lute, (a guitar–like instrument which was popular in the 16th and 17th centuries). Bach also wrote a version for keyboard. Like the Scarlatti sonata, it sounds great on guitar. The piece can be played with either right hand fingers, or a pick. It is recommended that you practice it both ways once you have learned it.
It is also recommended that you explore classical music in general, at least to some extent, even if you intend to concentrate on electric guitar. Many of the finest Rock and Metal guitarists, including Joe Satriani, Yngwie Malmsteen, Gary Moore, and James Hetfield and Kirk Hammett of Metallica, are heavily influenced by classical music.