The purpose of this study is to determine the lesson plan format, which the in-service teachers are using to develop their lesson plans, and how they are using their lesson plans during classroom instruction. The participants are in-service secondary teachers at a public high school in the Northeast United States. They represent a variety of subjects taught, years of experience, and education levels. The study includes three instruments for data collection: a nine-question survey, a four-question interview, and lesson plans from various teachers at the high school. These instruments were used to ascertain trends in the lesson planning process and format among the faculty at this high school. The data identify four elements of lesson plans that are crucial to a successful planning process: objectives, questions to ask students, materials, and an explanation of the warm-up activity. All of these elements share a common theme: practicality. When teachers include these things, they are the most useful during classroom instruction. This study acts as a springboard to further comparative studies, investigations of alternative methods of planning, and research into the impact of higher education on future teachers.