Be sure to use the citation style specified by your instructor. APA style is common among the social sciences.
A lengthy guide with examples, from the Purdue University Online Writing Lab. It gives examples and directions for most of the types of citations you will be creating. I do not recommend you use Chegg through their website.
Publication Manual of the American Psychological Association by 
The Bluebook: a uniform system of citation by Are you confused about when to cite? This video will help clear up your questions!
Direct link to "When do I cite?" on MSU Mediaspace
Video credit: Megan Kudzia
This video will walk you through what a citation is and the different parts of a citation.
Direct link to "Anatomy of a Citation" on MSU Mediaspace
Video credit: Megan Kudzia
Keep a personal database of books, journal articles, websites, and other resources with a citation management program. These programs will help you organize and keep track of resources as well as automatically format citations.