Principals new to their school face a variety of challenges that can influence their likelihood of improving their schools' performance and their likelihood of remaining the principal. Understanding the actions that principals take and the working conditions they face in the first year can inform efforts to promote school improvement and principal retention, but the research on first-year principals' experiences is limited. This report examines the actions and perceived working conditions of first-year principals, relating information on those factors to subsequent school achievement and principal retention. The study is based on multiple sources of data that were collected to support the RAND Corporation's seven-year formative and summative evaluation of New Leaders. New Leaders is an organization that recruits, selects, prepares, and supports school leaders to serve in urban schools. The authors found that (1) over one-fifth of new principals leave within two years, and those placed in schools that failed to meet adequate yearly progress targets are more likely to leave; (2) there were no strong relationships among principals' time allocation, student achievement, and retention; (3) teacher capacity and cohesiveness were the school and district conditions most strongly related to student outcomes; (4) principals' reported future plans were not strongly related to retention. Individual chapters contain footnotes. (Contains 4 figures and 24 tables.) [Funding for this paper was provided by New Leaders.]