Most libraries keep these books in the reference collection or even at the reference desk so students can access them easily. The print copies are the "official" guidelines for citing in your paper, though many websites are available to help with basic types of sources. Some of the best ones include:
The Chicago Manual of Style, 17th ed.
A Manual for Writers of Research Papers, Theses, and Dissertations, 9th ed. by 
MLA Handbook, 8th ed. by 
Publication Manual of the American Psychological Association, 7th ed.
Scientific Style and Format, 8th ed. by In this video you will learn the basics of how to evaluate resources, such as websites and articles.
Length: 1:12 mins Level: Beginner
In this video, you will learn why citing correctly is important for your research, and how to quickly analyze whether your own work falls in line with university guidelines about academic honesty.
Length: 1:34