This review focuses on characteristics of effective school library programs which significantly affect student achievement and which have the support of educational decision-makers. In schools with good resource centers and the services of a teacher-librarian, students perform significantly better on tests for basic research skills. The evidence is similarly clear that more reading is done where there is a school library and a teacher-librarian. School resource centers with full-time teacher-librarians even contribute to the development of positive self-concepts. The role of the teacher-librarian requires clarification if there is to be any improvement in existing programs. Teacher-librarians must have teaching qualifications and classroom experience prior to further education and training. The development of student competence is most effective when integrated with classroom instruction through cooperative program planning and team teaching by two equal partners--the classroom teacher and the teacher-librarian--yet communication is often lacking. There is also evidence that there are benefits to students when school and public libraries cooperate, yet public librarians and school librarians communicate very little. The research literature provides considerable evidence and guidance as to what constitutes effectiveness in the implementation of any desired change. A district policy to guide and support implementation and a district plan for a structured process can prove helpful. The implementation of change requires persistent advocacy and continual leadership and school support. With successful programs in place, teacher librarians can then assume more responsibility for writing about their role and about collaboratively planned programs for professional journals read by teachers and administrators. (Contains 88 references.) (AEF)