There are a variety of ways you can search for particular comic books in the library's catalog. In the search box, try searching for a particular character or title if you have one in mind. To browse, try running a search for su:Comic books, strips, etc. You may want to limit the results to items that Beloit College holds and sort the results by relevance as pictured here:
You'll find most comic books on the upper level of the library under the call numbers 741.5 and 741.59.