The biggest question will be in terms of your qualifications to donate. Right after that, you'll want to ensure that they offer proper confidentiality to protect you.
How many bedrooms, what utilities are included, and the commute routes to school. Is there a low crime rate? Is it close to a job source? The area will have an average rent, which you will need to look at. If you are getting room mates, rooms make a difference, if you can downgrade a 1 bdrm can work.