This manual is designed to familiarize data users with the procedures followed for data collection and processing of the base-year school component of the National Education Longitudinal Study of 1988 (NELS:88). A corollary objective is to provide the necessary documentation for use of the data files. The manual provides a wide range of information on topics related to the National Center for Educational Statistics (NCES) and the study at hand. More specifically, the report includes: an overview and history of NCES longitudinal studies, a general description of the data collection instruments used in the 1988 base-year study, the base-year sample design and weighting procedures, data collection procedures as well as schedules and results, data control and data preparation activities, data processing, organization and content of the data files and means of using them, guidelines for the Statistical Analysis System and Statistical, and several code books of school questionnaire data. The NELS:88 base-year study collected data from students, parents, teachers, and school administrators. Self-administered questionnaires and tests were the principal mode of data collection. The NELS:88 public use data files are available on four separate tapes, one for each study component. The tape for the school survey contains a file based on data for 1,015 schools. Seven data tables and seven figures are included. Appendices include the school questionnaire, a list of critical items in the school questionnaire, a record layout for the school questionnaire, specifications for the composite variables, and a description of related data files available from NCES. (TJH)