Remember to cite not only direct quotes, but also other people's ideas. If you paraphrase something, changing a few words to make it sound less like a direct quote, you still have to cite it. If you are uncertain, it is better to cite a source than to be accused of plagiarism for not citing something you should have.
APA
-
Publication Manual of the American Psychological Association. Washington, D.C.: American Psychological Association, 2001.
Reference Room BF76.7 .P83 2001
Reserve Desk BF76.7 .P83 2001
Floor2 BF76.7 .P83 2001 - APA Style Guide by Eric P. Garcia at California State University, Northridge.