Citing sources is a key part of your research; it documents what sources you have considered as part of your research, and gives credit to the author's work that you have used. It also gives information to identify and retrieve the cited sources.
A word of advice -- keep track of the sources you find from the first moment you begin the research process. Fortunately, many of the electronic databases you will be using offer the option to download, print or email the citations to the material you find but it is always more difficult to find 'the one that got away.'
There are many citation styles available and the preferred style varies between disciplines and instructors. In the case of RELS-312/812, students are required to use Chicago style.
Plagiarism is a serious offense. Citing your sources is one way to avoid plagiarism. To test your knowledge of plagiarism and how to avoid it, try this interactive tutorial created by Vaughan Memorial Library, Acadia University: