A lot of literature is adapted for the cinema. If you read a book and rent a DVD based on that book you’ll be able to compare and contrast. Here are just a few suggestions:
Marcel Pagnol has many excellent books that have also been made into films. La gloire de mon père and Le château de ma mère were autobiographical works made into films in 1990 by Yves Robert. In 1986, Jean de Florette and Manon des Sources were remade by Claude Berri based on films Pagnol made in the 1950s. Pagnol himself wrote the Marius trilogy first, for the theater and then for the screen.
The classic fairy tale Beauty and the Beast (La Belle et la Bête) written by Mme Leprince de Beaumont in her Contes de fées was made into a beautiful film by Jean Cocteau in 1946 (available on DVD). If you have only seen Disney’s version, you’re missing out.
Notre Dame de Paris by Victor Hugo has been made into many films, from the silent film with Lon Chaney as Quasimodo (1923) to the French musical which appeared on DVD in 2001.
Gustave Flaubert’s Madame Bovary has several cinematic adaptations. I suggest Claude Chabrol’s version starring Isabelle Huppert (1991).
Stendhal’s 19th-century classic, Le Rouge et le Noir (The Red and the Black) came out as a movie in 1997.
Henri-Georges Clouzot’s classic and shocking suspense/thriller Les Diaboliques is based on Celle qui n’était plus by Pierre Boileau and Thomas Narcejac.
Balzac’s novel Le Colonel Chabert was adapted for the screen in 1994.
Les Misérables, of course, has both film and stage adaptations.
Les Liaisons Dangereuses, my favorite 18th-century French novel, has many film adaptations in English, French, and Korean. Viewer beware, however. The novelist considered his work a highly moral cautionary tale, but some of the film versions might depict the immorality too literally for sensitive viewers.
And how about La planète des singes by Pierre Boulle? Not exactly canonical lit, but fun sci-fi.
There are many more to discover, but this should get you started.