The Wine Bible; Karen MacNeil
Great all around resource and jumping off point to more specialized and regional books. I highly recommend this book to anyone getting started in the wine trade as a reference and learning tool that is easy and enjoyable to read. I also find the recommendations of wines that show typicity to each of wine regions discussed helpful for wine tasting.
The Ultimate Guide to Spirits & Cocktails Hardcover by Andre Domine
This book is not simply a reference book and collection of recipes, but also a travel guide through the international world of spirits and drinks.
The World Atlas of Wine by Hugh Johns & Jancis Robinson
This book is quite large, but not overly daunting to read through a chapter or two a week. The info graphs are clear and assist in the understanding of the corresponding text. While there is beautiful photography throughout, my favorite part of this book must be the maps! They have a high level of detail, but are also easy to review.