It's important to give credit and cite the sources you used to prepare your paper. Historians and history researchers most often use Chicago/Turabian Style to cite their sources.
The Purdue OWL is a helpful free resource to help you create your citations.
Here's a general model for several Chicago-style citations:
Book
Kerouac, Jack. The Dharma Bums. New York: Viking Press, 1958.
Journal Article
MacDonald, Susan Peck. “The Erasure of Language.” College Composition and Communication 58, no. 4 (2007): 585-625.
Remember, you can also use SLLC databases to help you generate your citations!