An interpretive descriptive qualitative study was conducted to explore the characteristics and outcomes of mentoring used for implementing nursing practice guidelines. We interviewed six mentees, eight mentors, and four program leaders who were involved in the Registered Nurses' Association of Ontario fellowship program in Ontario, Canada. Inductive content analysis was used and study rigor was verified using triangulation of findings and member checking. Mentors were described as accessible, dedicated, and having expertise; mentees were described as enthusiastic, self-directed, and having mixed levels of expertise. The mentoring process included building relationships, developing learning plans, and using teaching and learning activities guided by learning plans to support development of mentees. Mentoring was described as positively impacting mentoring relationships, mentees, mentors, and organizations. A central feature of this fellowship program was the learning plan used to identify mentees’ needs, guide mentoring activities, and monitor measureable outcomes.