“Scaffolding is…a fluid, interpersonal process in which both participants are active participants [and] actively build common understanding.” 
Effective scaffolding requires one-on-one interactions, yet few classroom teachers can devote adequate time to individualized assessment and support. Volunteers can provide the help some students need to succeed. To maximize the benefits of volunteer tutors:
Volunteers should commit to a regular schedule.
Tutoring, like teaching, is relational work; relationships require time and trust. A tutor who comes once a week over the course of a semester or year will see their students’ progress and reap the benefits of their own gift of time. Allow tutors a few trial visits before requiring a long-term commitment.
Set aside 15 minutes for monthly tutor check-ins, either by phone or in person. Do you need to intervene with a discipline issue or provide some strategy instruction? Update tutors on upcoming schedule changes and have at least two communication modes (email, phone, text) for last-minute notifications.
Make sure tutors have access to class materials.
Provide texts, worksheets, assignments and rubrics. This allows tutors to prepare ahead of time and align scaffolding with clear goals and expectations.
Create a small community of support among tutors.
Tutors will benefit from each other’s experience and knowledge as well as the camaraderie. Provide a beginning of the year training session. Invite tutors to eat lunch in your classroom. Create a group email just for tutors.
Honor your volunteers with meaningful appreciation.
Validate the results of tutoring by reporting student progress and success. Many volunteers see their own learning as a tangible benefit, so include tutors in workshops or professional development opportunities as appropriate. There is no substitute for a hand-written thank you note, particularly one from a student.
 De Pol, J., Volman, M. and Beishussen, J. (2010). Scaffolding in Teacher-Student Interaction: A Decade of Research. Educational Psychology Review, 22, p. 272. doi:10.1007/s10648-010-9127-6