The present dissertation takes a multi-systemic approach to examining early childhood education, focusing on the child, classroom, and policy features in early childhood education settings that have the strongest potential to prepare children for school entry. Study 1 examines the extent to which a person-oriented approach to conceptualizing and assessing school readiness forecasts development in elementary school. Study 1 finds that six distinct profiles of 54-month school readiness patterns predict outcomes in 5th grade with indications of cross-domain association between 54-month performance and later functioning. Study 2 examines the relations between preschool classroom quality, measured by the ECERS-R, and child outcomes, and the extent to which there is a threshold in which the relation becomes stronger or weaker. Using a large, nationally representative dataset, Study 2 detects few direct relations or evidence for thresholds in the association between ECERS-R and age 5 outcomes. The association between quality and reading outcomes is stronger for children with sociodemographic risk. Study 3 examines relations between program quality and outcomes within a policy context. More specifically, Study 3 assesses the validity of Virginia's QRIS, the Virginia Star Quality Initiative (VSQI), by examining associations between 71 targeted pre-kindergarten programs in the VSQI and growth in pre-literacy skills. Findings indicate that children in higher-rated pre-kindergarten programs have sharper literacy growth in the preschool year compared to children in lower rated programs. Collectively, the studies in this proposal are complementary in that they each contribute to the larger question of how to improve children's readiness for school; however, they vary in study design, measures, and the focus within the early childhood system. (author abstract)