Well, I don't think it would take too many episodes to cover everything that happens in the book. I believe most books tend to be turned into 2-3 hour long movies instead of a TV series.
I know the film adaptation of 1408 was a bit different from the short story, namely in how the film mentions the main character having divorced his wife and lost his daughter.
I don't really watch it anymore myself. The only show I tend to watch now is Criminal Minds, although I have been watching Under the Dome lately to see how well the adapt the book into a TV series.