Korea Calling is a convenient guide for potential English teachers in South Korea. Separated in three 1)Getting a Job 2) Teaching English to Koreans; and 3) Surviving Korean Culture, the book is easy to use and very thorough. The Teaching section itself is a "greatest hits" of teaching ideas for the classroom, time-tested methods for teaching English to the Korean Market.
This book is somewhat outdated and pretty obnoxious in tone (the authors seemed so FULL of themselves!!) but the section on teaching EFL is great for anyone teaching English (not exclusive to those teaching in Korea!!) and there were a lot of great game ideas. The section on Korean culture, though, seemed a little more over generalized than other books/sources. A great tidbit to close, though:
In English-language fairy tales, we traditionally say 'Once upon a time..." In Korean-language fairy tales, they say "Back when tigers drank beer..."