Depending on what your reference is on eNotes, you can cite the source just as you would any internet source, which includes author (if given), title of entry, web address, and date accessed.

As for how to quote the article, if using the segment word for word, simply use quotations around the entire segment and attribute it in the sentence by telling where it comes from.  According to "author, or article title, website" and then the quotation.  Don't just say "According to eNotes".  The rule of thumb is can the reader find your exact source with your attribution or bibliography.