For an in-depth discussion of why citation matters and how to avoid plagiarism, see the following guide:
What does style have to do with citing sources?
There are quite a few different ways to cite resources in your paper. Citation styles consist of formats and rules established and modified by institutions and associations of scholars in various academic disciplines. These are the citation formats followed by writers and publications in corresponding fields. For example:
MLA style is typically used by most disciplines in the Humanities
Chicago/Turabian is generally used by History and Art
APA style is used by Education and Psychology
ACE or CSE are often used by the sciences.
Check with your professor to make sure you use the citation style that they require. And whatever style you choose, BE CONSISTENT! The Purdue OWL Research and Citation Resources Guideis a general guide that summarizes and provides basic examples of all of the styles listed here, and is a good place to get an overview.
Guides for Specific Disciplines:
Humanities and Social Sciences
APA (American Psychological Association) used in many social sciences · print copy · online
Turabian is essentially a simplified version of Chicago Style. Chicago/Turabian is a good choice for a general, all-purpose citation guide.
"Turabian" takes its name from Kate Turabian, the dissertation secretary at the University of Chicago for over 30 years who developed a guide for students and researchers writing papers, theses, and dissertations. This guide has evolved and has been revised many times, and, while based on the University of Chicago Press's Manual of Style, simplifies and departs from it in some aspects. Overall, "Turabian" synthesizes the rules most important for students' papers and other scholarly research not intended for publication, and omits some of the publishing details and options that "Chicago" provides, and presents some of the same material in a clearer manner.