Your instructor usually determines which style guide he or she wants you to use in your papers. If you don't know--ASK!
The latest print edition of the Publication Manual of the American Psychological Association is available in most of the University Libraries reference collections under the call number BF 76.7 .P83.
The online guide provides detailed examples on proper style and formatting for print and electronic articles, theses, dissertations, books, and more.
Print copies are still available at the Waldo Library Central Reference Desk Collection, Education Library and Music and Dance Library at Call Number Z 253 .C57.