The purpose of this guide is to inform the reader about critical issues facing radioactive and chemical waste tank cleanup in the U.S. Department of Energy"s Hanford Site in southeast Washington State. It is written as an information resource for general readers as well as the technically trained person wanting to gain a basic understanding about the waste in the Hanford tanks. Topics include waste generation, safety issues, and key technical issues facing tank cleanup. This guide provides such information without promoting a given cleanup approach or technology use. The guide makes liberal use of definitions, diagrams, sidebar comments, and cross-references to provide background information. Some general science discussion is also given.