The Novel is more Cannon than the movie
I recently finished the novelization of Batman Gotham Knight and IMO it is much better and better organized than the film. It mentions Ras Al Ghul a lot, Carmine Falcone, Rachel Dawes, and the events that took place in Batman Begins and applies it really well.
There is even a little mention of an infamous villain near the end of the novel and it is not Joker. I loved the film but in terms of considering a cannon story to Batman Begins and The Dark Knight I would say the novel does that pretty well. Makes sense why the Narrows wasn't shown nor mentioned in The Dark Knight and it is because in Batman Gotham Knight the Narrows is off limits to civilians due to the escape inmates still roaming around in Gotham City. Most of the escaped inmates aren't even captured in Gotham Knight.
I doubt this will be that important in The Dark Knight Rises but I love that the novel tied everything together between the six months before Joker made his presence known.