Answer: Little Women
Jo decides to call the book 'Little Women' and the novel is shown being printed and bound. She also inherits Aunt March's house after her death and turns it into a school which, unlike Plumfield in the book, takes girls as well as boys. Meg and Amy also teach there. The ending brings into question just how much of the film is real (so to speak) and how much is fiction, as it is implied that the scene with Jo and Bhaer, as Jo catches up with him and tells him she loves him as he is about to leave for California, is the scene Jo put into her book to pacify Mr Dashwood.
The decision to end the film with Jo publishing her first book has been suggested as an interpretation of the ending Louisa May Alcott really wanted for her, but was unable to write due to her publisher's demands. It may also be a reference to the fact that Alcott based some parts of 'Little Women' on her own life (Beth is based on her sister Lizzie, who also died young).