HyTech is a tool for the automated analysis of embedded systems. This document, designed for the first-time user of HyTech, guides the reader through the underlying system model, and through the input language for describing and analyzing systems. The guide gives several examples of usage, some hints for gaining maximal computational efficiency from the tool, and the complete grammar for the input language. The version of HyTech described in this guide was released in August 1995, and is available through anonymous ftp from ftp.cs.cornell.edu in the directory ~pub/tah/HyTech, and through the World-Wide Web via HyTech's home page http://www.cs.cornell.edu/Info/People/tah/hytech.html