You will go to the School District office and sit at the head of a long table. Every principal of every Jr. High or High school that is hiring for your position will be there. Each one will read off a pre-written question from a page. They will go around the table one at a time asking through the questions. They cannot ask anything more than what is on the page. You are allowed to ask them questions.
MOST of the time you already know a principal/school because you've student taught there or you taught there the previous year. Which means you will probably be hired at that school, especially if your principal has told you so. The interview process is often a formality.
If you are new to the district, your chances will be a bit low on getting hired. Questions range from "What made you want to get into teaching?" to "How would you deal with a continually defiant student?"