Recommended for your first pedagogy book purchase:

• Music Educators National Conference (1991).  Teaching Stringed Instruments:  A course of study.  Reston, VA:  Author.  Good book for beginning string teachers, because it is very brief, contains table of scope and sequence of instruction and contains suggestions for  more in depth study.

• American String Teachers Association with National School Orchestra Association (1997).  String syllabus.  Bloomington, IN:  Tichenor Publishing  resource for additional music for students.  Something available for high school mentors to use if they needed to find more music for their students.
• Green, E.A.H. (1966). Teaching string instruments in classes.  Bloomington, IN:  Tichenor Publishing - pictures of hand positions, games to teach technique and excellent pedagogical sequence
• Music Educators National Conference (1996).  Strategies for teaching strings and orchestra.  Reston, VA:  Author  sample lessons that are aligned with the National Standards for all levels of string instruction.
• Rolland, P. (1974).  The teaching of action in string playing. Urbana, IL:  Illinois String Research Associates.  pictures of hand positions, games to teach technique and excellent pedagogical sequence.
• Young, P. (1986).  The string play: the drama of playing and teaching strings.  Austin, TX:  University of Texas Press. lots of creative games for teaching string students.