You fill out an online application, take tests in the subjects you want to tutor, provide a writing sample, and do a mock session. It is best to initially take exams for subjects you wouldn't mind having your mock session in. You can always add extra subjects later. The mock session process was pretty simple. I requested a mock session and the mentor promptly accepted the session date. During the mock session, the mentor first gives you some prescripts about what is going to happen and other basic info. Then, she/he poses as a student and asks one question from a subject that you passed. After 20 minutes, the mentor tells you you can stop and goes over some more general information about tutoring.