Overwhelmingly, research shows that program quality is a major determinant in the achievement gains for young children who participate in early education programs. Teacher quality, in particular, is closely related to positive educational outcomes for preschool participants. Research shows that children in programs whose lead and supporting teachers have higher education qualifications and ongoing professional development show the greatest gains. Also, research shows that the use of developmentally appropriate curricula predicts program quality, as does a high degree of direct instruction that comes from smaller staff-child ratios and focused small group activities. Evidence suggests that these positive outcomes benefit a diverse range of children from various racial, ethnic, and socioeconomic backgrounds. The development of Quality Rating and Improvement Systems (QRISs) shows promise in giving states a tool to assess program quality accurately and link together disjointed components of early childhood education systems. This annotated bibliography provides a sampling of research on policy topics with nationwide applicability. The resources are organized into the following topics: (1) The importance of program quality on educational outcomes; (2) Teachers build the foundation of pre-K program quality and success; and (3) The role of states in monitoring program quality--Quality Rating and Improvement Systems (QRISs).