"Scholarly or focused critical writing about particular films--both current and historical--can be found in an amazingly wide variety of sources, including film journals, and publications devoted to theater, history, literature, women's studies, ethnic studies, and other disciplines. Critical/analytic film articles tend to be more academic and substantive than reviews. These articles often discuss particular films in broad social, political, and historical context. Many times the focus of these articles is on a fairly specific aspect of a film or a film genre." (Source: http://www.lib.berkeley.edu/MRC/filmstudies/filmreviewsintro.html)
To search the journal literature for more in-depth treatments of films, actors, actresses, directors, film genres, etc. try these databases:
NOTE: Remember these databases will also have information on the original written work if the movie was based on a book. You can search by movie title, actor names, director, or genre to find resources.
There are also some good journals now available on the "free Web" including: