The Essential Bartenders Guide
by: Robert Hess

Mud Puddle Books

The Essential Bartender’s Guide is a great overview guide on proper technique, details, recipes, and overall mixology guidance that almost anyone, regardless of their skill level, will find useful.

The Oxford Companion to Spirits and Cocktails
by: David Wondrich, Noah Rothbaum

Oxford University Press

An extremely important encyclopedic compendium of information on virtually everything related to cocktails and spirits.