Try LoopNet or Zillow. Find the college and then search nearby. When using Zillow select apartments.
I would work on narrowing your market down some. The Midwest is big and with 240,000 you have a lot of options, even with the criteria of being near a college. I know that in the Midwest city that I invest in 240,000 would get you a 5 unit near a college. Here's an example:
1115 Woodlawn Ave, Springfield, OH 45504
10 beds 5 baths 6,042 sqft
Duplexes in this same city will run you about $50,000. If you paid $240,000 you would have be taken advantage.
I would recommend that you partner with someone who is familiar with the neighborhood you are investing in. One block might be good and the next block over might be rough. Sometimes it even matters what side of the street you are buying. Some colleges will not allow student to live off campus, if that's who you want to rent to.