In order to provide context for your chosen items and inform your commentary, you should look for additional (outside of class readings) tertiary and secondary sources that explain the context for the example/artifact. You can find keywords and larger framing ideas in the course reading and then look them up in the library catalog and subject-specific databases, looking for scholarly articles and books/book chapters that help frame your commentary about your items.
An interdisciplinary journal archive. It includes archives of over one thousand leading academic journals across the humanities, social sciences, and sciences, as well as select monographs and other materials valuable for academic work. Includes the Artstor image collections.