Living on campus for the first year is pretty useful; you literally are next door to the school. The downside is the apartments are in dire need of renovation and they are dingy units. That being said - you will come away with some good memories if you decide to live there, but there are many options if you are willing to walk 15 minutes or so to school.
I would stay away from the apartments across the street from the school located on the corner of Cherry & 9th. They are pretty run down and a couple of classmates apartments were burglarized.
Some decent and affordable apartments can be found littered across South street near Old City. The rent is somewhat comparable to what you would end up paying at campus housing per month for a single unit apartment; bear in mind at campus housing you pay one large sum for the semester that includes everything [water, electricity, internet, cable, rent]. Convenient.
If you can afford it, Nine North Ninth is pretty decent. It is the apartment building situated across from the Gallery on the corner of Arch St & 9th. I knew quite a few people who lived there and none were too displeased. Its just really, really expensive.