Magazines or journals?
If your professor asks you to use scholarly information for your paper, you should choose a journal rather than a popular magazine. Journals are written for experts and researchers in the academic or professional communities. An editorial board of respected scholars reviews all articles submitted to a journal. They decide if the article provides a noteworthy contribution to the field and whether it should be published.
Some magazines -- such as The New Republic, Harper's and Scientific American -- can also be good sources of information for your paper. They are written for readers who, although not experts, are knowledgeable about the issues presented. Articles in these sources are generally more in-depth but still fairly easy to understand.
Popular magazines like People, Sports Illustrated, and Rolling Stone are probably not the best sources to use to find articles for research.