Five research studies on teacher planning are reviewed to discover how basic descriptive research can inform the practice. Seven findings are discussed: (1) Planning is important to teachers and generally invisible to everyone else; (2) Planning differs in practice from traditional prescriptions for planning; (3) Planning during the first weeks of school has long range effects; (4) Teacher planning transforms curriculum into instruction; (5) Routines increase teacher efficiency and flexibility; (6) Communicating plans puts thought into action; and (7) Teacher reflection aids teacher development. (Author/CJ)