Reference resources are a great place to begin your research. They can help you define terms as well as find overviews of topics and theories and identify keywords or alternate terms for database searching.
There are many different types of reference sources, which include dictionaries, encyclopedias, thesauri, bibliographies, handbooks, style manuals to name a few.
Check out the links located under Reference Resources for information about these individual resource-types.
Oxford Bibliographies offers peer-reviewed annotated bibliographies which will help you to narrow the vast number of citations to the best scholarship on a given topic.
Bibliographies are browseable by subject area and keyword searchable and list books, journals, primary documents, web resources, and multimedia in various discipline-based subject modules, including a Communication module.