The King County Library System employs over 1200 staff members in 49 different branches. Our sponsors in the Staff Development Department felt that a formal mentoring program could prove beneficial in such a large, dispersed organization; but to design an effective program they needed information about staff needs and mentoring best practices. Our team gathered this information by conducting focus groups, researching mentoring literature, and benchmarking organizations’ mentoring practices. Taking all that we learned from these investigations, we built a set of recommendations that will facilitate the creation of a successful and sustainable mentoring program at KCLS.