Normally,I wouldn't recommend an online course, but I trust the folks at Asian EFL Journal. It is a very well run website with contributions from teachers who are seemingly well accomplished in the field. I enjoy the material I read there immensely and have learned a lot about the EFL scene in Asia. The books they are offering with the course seem very appropriate. And the videos should be a real plus. Hopefully, they will encourage communication between you and the staff while taking the course. I would recommend that, should you decide to take the course, you couple it with some volunteer work or internships - most ESL or EFL teachers would be happy to have you sit in on their classes and would give you any guidance you ask for. I would also recommend that you talk with or email any past students they've had and get some serious feedback.
Good luck.