Howard Hughes Medical Institute book
Making the Right Moves
http://www.hhmi.org/grants/office/graduate/lab_book.html
How to be a lab head, including mentoring and being mentored (Chapter 5)

USA Committee on Science, Engineering, and Public Policy (COSEPUP) book
Adviser, Teacher, Role Model, Friend on being a mentor to students in science and engineering
http://www.nap.edu/readingroom/books/mentor/

This guide - intended for faculty members, teachers, administrators, and others who advise and mentor students of science and engineering - attempts to summarise features that are common to successful mentoring relationships. Its goal is to encourage mentoring habits that are in the best interests of both parties to the relationship. While this guide is meant for mentoring students in science and engineering the majority of it is widely applicable to mentoring in any field.
 
This guide is meant to assist mentors and advisers in understanding how they might help students identify and respond to the challenges of becoming scientists or engineers.

COSEPUP has also developed a sample form to help evaluate faculty mentors. The form can be adapted by individual institutions to suit their own needs. The version of the form offered here is most appropriate for use by advanced graduate students (for example, third-year and higher PhD students), postdoctoral fellows, and recent doctoral-program graduates who have had a long relationship with a mentor.

Carfax Publishing produces a journal
Mentoring and Tutoring
http://www.tandf.co.uk/journals/titles/13611267.asp

Mentoring & Tutoring provides a resource to exchange information on mentoring and tutoring particularly in schools, further and higher education, hospitals, industry and the management professions. Mentoring is beginning to play an important role in burgeoning ‘distance learning’ programmes and is increasingly recognisable in many countries throughout the world.