Alternate Chord is a very powerful and excellent music score chords tool designed specifically for practicing guitar chords and guitar scales, developed by Alternate Tools from Germany. It has a clear and intuitive interface, includes a variety of different chords, allows the addition of your own scales and chords, and provides the possibility to listen to scales/chords through the MIDI interface. Better yet, it's free and open-source.

Beginning Fingerstyle Blues Guitar is a classic and excellent  tutorial book (published in 1993) for playing the acoustic blues guitar. It broke down the whole learning process of fingerstyle blues step by step in only 98 pages and was written especially for beginners.