This is a seminar on teaching and learning for undergraduate teaching assistants (TAs) of CSci classes. Enrollment is by instructor or department permission. The course's main goal is to help TAs improve their knowledge of teaching and learning in computer science so they can be effective TAs. Topics covered include educational issues in computer science, TA professionalism, best practices in giving effective feedback, inclusive teaching, online teaching and learning, and how to communicate well with students and other course staff. Its secondary goals are to help TAs improve their own communication skills, leadership skills, and knowledge of computer science as a field.