Interpretation of Dreams, The - Full text of Freud's book on dream interpretation, published in 1900 and based upon research with his psychology patients.
PBS.org: Freud's Book - The Interpretation of Dreams - Explains the history behind Freud's release of The Interpretation of Dreams and its core ideas. Though many posit this to be Freud's most important contribution, it took eight years to sell 600 copies.
Wikipedia: The Interpretation of Dreams - User-generated article about The Interpretation of Dreams, the book in which Sigmund Freud introduces the concept of dream analysis to explain the Unconscious.