I am currently an ESL teacher but with Call Center Quality Control background which entailed listening to calls and make suggestions with regard to voice, language usage and product knowledge, as well as rate the advisers.
However, when it comes actually teaching English by phone I am clueless. Can anyone point me in the right direction; online books or websites that might be of help.
Here are some sites that do it: Tutorials - ESL Web Directory - UsingEnglish.com
What sort of syllabus/materials are you using?