Adelphi University Librarians created a guide to assist students with their research. Make use of the tabs at the top of each section--they provide guidance through the research process, including how to formulate your research topic and how to find sources by type.
Nassau County's public libraries, including Henry Waldinger Memorial Library in Valley Stream, have a shared catalog. This means you can borrow books and materials from any of the public libraries in Nassau by using your Valley Stream library card. The librarian there can also help you get materials from LI Link or elsewhere.