Quotations: You may quote sections from the work(s) that you are considering in your paper. Be sure to specify the page number. It is often useful to include a few quotations to assure the reader that you are sensitive to the text, but too many quotations are distracting.
Paraphrases: If you paraphrase an idea from another source, footnote it as if it was a quotation.
References: Include references at the end of your paper where needed (when you quote out of a book or article). Use whatever professional style you are most comfortable with. My favorite is the American Psychological Association journal style.
Examples:
Rummelhart, D., & McClelland, J. (1986). Parallel Distributed Processing. Cambridge, MA: MIT Press.
Smolensky, P. (1990). Tensor product variable binding and representation of symbolic structures in connectionist systems. Artificial Intelligence, 46, 159-216.
Ideas due to Others: If someone gives you an idea, or if you have a lengthy and illuminating conversation with someone on the topic of your paper, be sure to credit her in a footnote. You may simply write, for instance, “This idea is due to Professor Jana Sawicki, in conversation.”