Take a look at the following readers, publications and project manuals of mentoring in Europe.
MentorProgramma Friesland: Enriching relations, 2014
MENTOR: The National Mentoring Partnership: Elements of Effective Practice, 2015
Mentoring in Europa, Project SUPREME, SUPREME Manual, 2014
European Mentoring and Befriending Exchange Programme, EMBEP manual, 2015
Sirius European Network of Educational Support Projects, Mentoring for migrant youth in education - a handbook, 2014
For an overview of research on mentoring, please check the website of the US Center for Evidence-Based Mentoring and the website of prof. dr. Jean Rhodes.
You can keep posted on mentoring research and practice by subscribing to the Chronicle of Evidence-Based Mentoring.