"The Notebook" is not available for free through legal sources in the United States as of 2015. The film is under copyright, and it is only possible to view it legally by purchasing it.
Apple iTunes and Amazon.com Instant Video both offer "The Notebook" for digital purchase. Amazon.com Instant Video also offers it as a digital rental. It is available from Amazon in both standard- and high-definition; the standard-definition version has a lower price. Apple sells only the high-definition version of the movie and does not have a rental option.
"The Notebook" is also available for purchase on DVD and Blu-Ray at Amazon.com