An annotated bibliography is a list of citations to books, articles, and documents. Each citation is followed by a brief descriptive and evaluative paragraph, the annotation. The purpose of the annotation is to inform the reader of the relevance, accuracy, and quality of the sources cited.
Purdue OWL's website explains what an annotated bibliography is and also gives you an example of what a Chicago annotated bibliography could look like.
For your class assignment you will need to include 6-7 sources on your annotated bibliography. Underneath each source explain in 1-2 sentences what research question it could help you answer/what information it contains.