I would go with about any book by Rick Bayless. If you're not familiar with Chef Bayless, he's a James Beard Award winner and the winner of Top Chef Masters. His most recent book, "Frontera" is very heavily loaded with beverages. I would lean toward "Mexican Everyday" as a good starter, though I love all of his cookbooks.
Also, "Truly Mexican" by Roberto Santibanez is pretty fantastic too.
If you start with those, you can then determine if there is a particular regional type of Mexican cooking (e.g. Oaxican) or style (e.g. street food) that you'd like to learn more about.