I found a place her- they're new apartments that are going up about 4 miles north of campus: www.seasonstucson.com
-They will be ready for move in the first week of August.
As far as finding an apartment through an agent, I think you really have to see the place yourself, before you can really decide. There are so many areas of town where you don't want to live, even though the apartment itself can look good, the area is terrible. For example, west of I-10- there are nice aparments, but the area is run-down and you end up always driving back from across town just to go out to a restaurant.
I know a lot of students live on River road between 1st and Campbell. There are several large apartment complexes there and a new one is opening up in July right on River about a block east of Campbell (can't think of name right now, sorry)
Good Luck and just don't live on the west side or too far east or south (anything past Swan is too far and don't live too far south- anything past Broadway is too far)