First off--make sure you have clear expectations of the job -- How success is measured/what quota you are expected to meet, what happens if you don't meet it, what is the path to promotion, understanding the commission-based pay structure. Secondly, ask questions that you would ask of an organization before donating money to them -- understanding the credentials of the organization, how the funds you raise are used, etc.
The best question to ask a student interviewing for Ruffalo Noel Levitz is "How do you deal with rejection" or "Please provide an example of a time that you faced rejection, and how you handled it.". I chose those questions because almost every individual you call will reject you/treat you poorly via the phone, and students should be prepared that experience. Another question could be "Are you comfortable in a competitive work environment?" or "Are you comfortable asking people for money?". These questions are relevant because the work environment is incentive based, meaning if you don't get through a complete call in a certain amount of tries you are bumped down to a harder tier of caller, which creates a competitive nature between the students working. As for the asking for money, I didn't realize how uncomfortable this made me until I had to ask an alumni for $5,000.
The main question would be to ask about the hourly commitment. I worked part time at this position, and the hours were 6PM-9PM, with an option to come in during the day as well from 1PM-5PM. This is a flexible schedule but may not be exactly what someone is looking for. Additionally, there was some room for limited growth within the company. There was no automatic structural promotion in place, but there was an automatic pay raise at certain milestones of length with the company. It is important to ask how you can grow your career with the company, and not get stuck in one position at a dead end.
How many hours a week am I required to have?
May I do outside work when calls are low? Will you work with my school schedule?
Would I need to find someone to cover my shift if I’m unavailable?
Will I be punished for missing shifts?
This job is one of the most important jobs for the university, how much will I be paid and are their raise opportunities?
What days of the week will I be working?
Can I take up more shifts than required?