The purpose of this Guide is to help those receiving data and data products from the National Oceanographic Data Center (NODC) to make better use of the material obtained. In addition, it should help data requesters to intelligently formulate inquiries based on a knowledge of the capabilities (and limitations) of the data base. Chapter I of the Guide is the introduction; Chapter II contains the general procedure for handling data requests; Chapter III describes the physical-chemical data processing; Chapter IV the BT data processing systems--digital; Chapter V the geology core, grab, and dredge information system; Chapter VI the biological information systems; and Chapter VII discusses future plans for NODC. A short glossary of terms is also included. (Author/NH)