The ELT Manager’s Handbook
This is, as far as I am aware, this only book for EFL managers on the market. Luckily, it is well up the job- with lots of very practical tips for managers at any level. It is slightly more useful for managers in continuous enrolment schools such as those in the UK, but it is certainly a more useful and easier read for any EFL manager than general management theory books. If you are a manager that still teaches business students, it is also a great way of relating what you do to your students’ world.