If you are a bartender, I highly suggest you read, "The Joy of Mixology" written by Gary Regan. The book was recommended to me by a fellow bartender. I started reading it last week and haven't been able to put it down. This book has everything one would ever need to know when it comes to bartending. This book discusses the history of cocktails and mixed drinks, what every bartender needs to have or be able to do, the theory of mixology, foundations of the bar (garnishes, mixers and supplemental ingredients), bartending tools, glassware, a very clear explanation and chart of cocktail and mixed-drink families and hundreds of recipes.
Do yourself a favor and don't just skip to the recipes chapter. Really read this book from start until finish. I have read a few different bar books and I feel like this book really gives it's reader the whole spectrum of how things work and function behind any bar. I have been bartending for a few years and thought I knew a lot about bartending and cocktails already. Now that I am reading this book, I am realizing that I still have a whole lot more to learn. I love books that expand my horizons!
The book itself is easy to read and hard to put down. It isn't super long either. I wish I had known about this book when I first started bartending.