Choose a topic that is interesting to you and which will work within your assignment's parameters. Usually your research goal is to locate published scholarship (books and journal articles) to read on your topic.
Remember to evaluate the accuracy of your resources, and think critically about their arguments. When in doubt, check with your instructor in the Hispanic Languages and Literatures Department.
First, read a good summary of a your topic in an encyclopedia, like those listed in the Books section. Second, once you know the basics on your topic, search for more published scholarship, such as books in the CUNY Catalog or other catalogs.