This trip was taken in May of 2012. El Chepe (the train that follows the Copper Canyon is an incredible journey. An amazing engineering feat, it also takes passengers through a wonderland of scenery. The most marvelous section goes from El Fuerte in Sinaloa to Creel in Chihuahua. We (4 friends) started our journey in El Fuerte (although this last week April 2013 locals in Alamos warned us about driving to El Fuerte). We stopped at Posada Barracas for an overnight and also in Creel before returning to El Fuerte. In Creel, one can find guides to take you into the canyon and to see other sights.
If you do not stay at various stops on the train, you will only get to see the main part of the canyon on a 20 minute stopover at Divisadero. Although there is a hotel there, I prefer the Posada Barrancas just before the Divisadero stop. The price of the rooms there are worth it for the many amenities you get (3 meals, tours), including every room situated on the edge of the Canyon.
Make sure you take the cable car between Posada Barrancas and Divisadero.
I prefer the First class seats. They are very large and comfortable and the dining car had booths to sit and relax.