In a recent "Journal of Early Childhood Teacher Education" article, the author reported on a single case of a successful mentor-beginning teacher pairing that was derived from a larger qualitative study (Certo, 2005). The purpose of this article is to report findings from that larger investigation. Three Virginia elementary 1st-year teachers and their mentors were interviewed in September, December, and February. Beginning teachers also kept journals of reflections about challenges in 1st-year teaching and the presence, nature, and impact of mentoring activities. Perceptions of mentor activities and the perceived impact on beginning teachers' thinking and professional development are described using Daloz's support and challenge model (1988). Mentors provided a balance of support and challenge activities, and beginning teachers reported being impacted by their mentors in numerous ways, from classroom management to adoption of new instructional approaches. These cases may be useful to practitioners as models of effective practice. (Contains 4 tables, 1 figure and 1 footnote.)