Your professors will require that you correctly cite your sources. The following links will give you guidance on when and how to cite as well as examples of the various forms of citations in common usage such as MLA, APA and Chicago Style.
This guide from Duke University gives clear examples of citing different sources in the major citation styles, APA, MLA, Chicago, Turabian, and CSE.
The links from this guide will take you to a wide variety of citation guides, some general some designed to help very specific disciplines.
This link will take you to several brief tutorials on Proper Usage including citing, understanding a citation and how to cite.