Opposing Viewpoints Series
This series of books looks at contentious contemporary issues and provides both points of view. Each book covers a different topic. To see if there's a book on your topic, have a look at the small sample below, or try searching in the library catalog with "opposing viewpoints" in the search (for example: "opposing viewpoints" AND abortion).
Issues that Concern You Series
Yet another series of books focused on contentious current issues. Though not written for an advanced audience, the books are well-researched and include helpful organization and website links. As before, check the library catalog to see what's available on your topic (ex: "issues that concern you" AND vegetarianism). Some titles from the series: