This document presents YODA, an approach for identifying mentors in open source software projects. It aims to address the challenge of finding suitable mentors for newcomers joining large projects. YODA analyzes project data like mailing lists and version control systems to identify factors that characterize past mentors. It then uses these factors to recommend potential mentors for new joiners. An empirical study on five projects found communication-related factors like email exchanges are useful for identifying mentors. A survey of developers indicated mentoring is important and that technical skills and communication ability are key qualities of an effective mentor. Future work could focus on improving YODA's recommendation capabilities.