Arabian Nights (and Days) introduces the world of the arabian fables to Fabletown. We get to see that not all worlds are under the sway of the Adversary, and that not everyone is thrilled that the arabian fables are going to cooperate with the american fables. We also get to learn a little more about the wooden soldiers, as well as get to see more of the wonderful Frau Totenkinder (easily one of the most interesting characters in the series). 
 While this isn't a good place to jump into the series, I'd still recommend this to anyone. Fables is easily accessible to even the greenest comic book fan or to a person who has never picked up a comic book before in their lives.