Helpful citation guides like The Writing Center guide from the University of Wisconsin-Madison will provide assistance with the most basic and frequently cited materials. For additional and more obscure material types, search Google, as many other citation guides exist from university to university. See the below screenshot as an example.
Citation managers like RefWorks, EndNote, Mendeley and Zotero help you track and organize your citations, so that when you're writing your paper, you can easily cite your sources. Citation managers also help you insert citations, create endnotes and bibliographies.