This guide describes 10 important features of successful mentors' attitudes and styles, using data from an examination of 82 pairs of mentors and adolescents in Big Brothers Big Sisters mentoring programs nationwide. The key reasons that certain mentoring relationships succeeded while others failed was related to the expectations and approaches of the mentors. Successful mentors understood that positive changes in the lives of young people would not happen quickly or automatically. If they were to happen at all, the mentor and youth had to meet long enough and often enough to build a relationship that helped the youth feel supported and safe, develop self-confidence and self-esteem, and see new possibilities in life. The 10 necessary features include: be a friend; have realistic goals and expectations; have fun together; give the mentee voice and choice in deciding on activities; be positive; let the mentee have much of the control over what the two of them talk about and how they talk about it; listen; respect the trust the mentee places in the mentor; remember that the mentor's relationship is with the youth, not with the youth's parents; and remember that the mentor is responsible for building the relationship. (SM)