"Maintain high standards of ethics and professionalism: Mentors and mentees must strive to uphold appropriate ethical behavior as professionals." 

Best practices for ethics and professionalism in a mentoring realtionship:

• Promote mutual respect and trust
• Maintain confidentiality
• Be diligent in providing knowledge, wisdom, and developmental support
• Carefully frame advice and feedback so it is well-received and constructive

From Amy Greil's "A Story of Mentoring" found online at http://www.kenoshanews.com/news/amy_greil_a_story_of_mentoring_493097750.php

As a mentor, think carefully about feedback you want to give to your protégé. Try to create a balance between positive encouragement, and critiques on areas that need improvement.