The purpose of this document is to develop a usable science teaching guide based on the process skills methodology for the middle school life science teacher. It is intended to provide an efficient and effective tool for the interested teacher to use to develop the skills of the methodology. It could also be used as companion to the latest set of science and health competencies issued by the New Mexico State Department of Education, and as a supplement to life science textbooks. Part I, "Science in the Contemporary Classroom," presents a theoretical foundation for teaching science in a middle school classroom. Part II, "Life Science in the Las Cruces (New Mexico) Middle School Classroom," provides a model for incorporating process skills into teaching. Both parts are an effort to further the use of the process skills approach in a middle school life science program, which will be achieved as teachers come to believe that the outcomes justify the effort. A summary is provided in the form of a concept map, developed to show the relationships between the key ideas. (TW)