There are two to three interviews. They have normal questions. Do you research on the specific division. The education school has set salary so there often is not room for negotiation.
I applied through university. The process took 3 weeks. I interviewed at Harvard University (Cambridge, MA) in Apr 2014
Interview
There are plenty of questions about what potential one-on-one experiences between you and applicants will look like. Understanding the student experience and potential opportunities at Harvard are essential but not having personal expertise is not a deal-breaker.
Interview questions [1]
Question 1
I don't remember the questions exactly but explaining your interest in the position and capabilities to perform was stressed.