If you're searching for an interactive, informational, student-directed research project before reading (or even while reading) To Kill a Mockingbird, this is the assignment for you! This is a quick background research project for small groups to learn about important topics of discussion related to the text. This product is a student handout which contains instructions for the research project as well as a standards-based, customized rubric.
This project can also be adapted to suit your class's needs. I have students research using computers and create an Power Point or Prezi style presentation, but this would be extremely easy to make into a poster presentation. I have even created a whole class Google Slides Presentation and shared the link with my classes so that it forms one giant presentation instead of many smaller ones (I find that my inbox can get cluttered easily if I have too many presentations shared with me)—I would highly recommend this method as well.