Focusing on the teaching of computer science in the generative A.I. (GenAI) era, the 4th edition of this Guide to Teaching Computer Science aims to contribute to the urgent effort to rethink and redesign computer science education. This Guide to Teaching Computer Science is intended for all computer science educators, from elementary, middle and high school to academia. It is organized in a way that enables an immediate application of its main ideas. This goal is achieved by presenting the rationale for addressing a variety of computer science education topics, as well as their detailed actual teaching process (including activities, worksheets, topics for discussions, and more). The rise of GenAI necessitates immediate changes in computer science education, even as we recognize that predictions about the future of the discipline of computer scienceâand of educational systems more broadlyâmust be made with caution. · The guide focuses on computer science education â teaching and learning. · The guide is organized in three parts: Overview of Contemporary Computer Science Education; Computer Science Education Pedagogy: Research and Implementation; and Teacher Preparation Frameworks. · Each chapter presents a pedagogical topic along with its meaning, importance and relevance in the context of computer science education, its basic pedagogical principles, and how it can be applied in computer science education in generalâand in the Methods of Teaching Computer Science (MTCS) course in particular. · Topics addressed in this guide include the following in the context of computer science education: research in computer science education; learnersâ alternative conceptions; types of questions; assessment; teaching methods and learning spaces; lab-based teaching; teaching planning; teacher preparation programs; and prospective teachers practicum. The 4th edition of this highly useful guide includes 232 activities. This unique resource can be used by many people involved in computer science education: in particular, instructors of an MTCS course, instructors of in-service teachersâ professional development programs, and teachers across all levels and students.