Expect to be contacted by an American by email. He will talk very fast like a salesman during the first interview, so just set back and listen. Don't ask a lot of questions. He may claim to be in their HR department, but in reality he is an instructor and trainer.
They will call you in for a very brief interview. Don't expect them to read your resume, or ask any relevant interview questions. They are just fishing for a follower that they can ask to do anything without questions, or opinions.
They will ask you to come in a second time to give a very awkward presentation demo for 15-20 minutes. It is usually a very vague topic. Be prepared to present to a few office girls who are very shy and don't have a very good grasp of English. At the same time, the boss will observe you and take notes.
After your short demo try and ask about the job, company, or corporate enviroment. They refuse to give you any details and dance around any questions about pay, hours, or compensation.
You would expect the same professionalism from them that they show their corporate clients, but in researching the company and chatting with current and past instructors, you find out what really goes on behind closed doors. I encourage you to do the same...