@martini mentioned this one - The New Orleans Cookbook, which seems to be a classic. Buy it used if you can because the format is very simple and text-heavy. I have yet to try any of the recipes, but I read through them and they seem solid and easy to follow.
If you are more of a visual person, I would recommend Besh Big Easy. The recipes are really approachable, and the book itself is very enjoyable to flip through.
