This is a sequel to The shambling guide to New York, but probably works as a stand-alone, too. References to previous events are not crucial to understand what's going on, although I think you should read it in any case, because Mur Lafferty's funny, her books are short and sweet, and her urban fantasy is populated by some charming incarnations of zombies, ghosts, gods, sprites, vampires, succubi, and other tropes - as well as a few original natives. (And, hey, look at the cover. I have a soft spot for the shambling covers. All colorful and cartoony and stuff.)
Zoe is a travel guide writer who has, more or less accidentally, ended up working in a company where most of her colleagues would like to eat her. It makes for interesting work days. And maybe things are more complicated than that. That's the basic premise of these books, and, I think, all you need to know in order to decide whether or not this is of interest to you.
If you do need additional clues about Ghost train to New Orleans, here are a few: Ghost train. New Orleans! Swamp voodoo, vampires, costume parties! Oh, and cats. How could I forget the cats!
The narration and feel is something adjacent to the Buffy kind of monster affairs, at its most quippy. Or the comedy-relief episodes of, uh, Supernatural. There is action and adventure and even character deaths, but it never slows down to dwell or mourn, at least not for longer than it takes for Zoe to have a drink or three. There's good forward movement and the pages fly by.
Mur Lafferty offers this book for free, self-narrated, via her podcast. (The podcast is named I should be writing, and you can find it if you search from whatever thingamabob you use for podcasts.) I listened to the first few chapters, then I decided to buy the book, mostly because yes, she has earned my measly not-even-eight dollars for a kindle copy, and also because I wanted to read it faster.
Consider a shambling guide for when you want a fun read that doesn't take your brain for a heavy workout. (I mean this positively, of course; light reads are not bad reads.) Stay away if you can't handle even one more vampire or zombie in your book shelves. (But keep in mind these are pretty cute zombies.)