On each page of information on Enotes, there is a link showing how that particular page can be cited. This link can be found directly underneath the title on the page, the third link, labeled "Cite this Page." A pop-up box will appear when the link is clicked, entitled "Cite this page as follows." The pop-up will show the proper format for a citation, along with a brief explanation on important information to include when citing website articles such as these.
Look, for example, on the link referenced below, the Introduction for the John Knowles novel, A Separate Peace. Notice on the line directly underneath the page title, "A Separate Peace/Introduction," the five icons with links provided, "Printable Version," "Downloadable PDF", "Cite this Page," "Ask a Question," and "Tweet This." Click on the third link, "Cite this Page," and a pop-up will appear, giving you the information requested.