To select an aromatherapy book, take into account both your level of experience with essential oils and what you want to learn. Some books offer more or less background information, while others are mostly a collection of aromatherapy recipes.
This article lists the aromatherapy and essential oils books I have found to provide the best overall information. If you're interested in aromatherapy training, here's a list of programs.
For beginners, Aromatherapy for Dummies by Kathi Keville offers good, basic information, along with some recipes.
If you prefer something a bit more sophisticated yet still basic enough for someone new to essential oils, take a look at Healing With Aromatherapy by Marlene Erickson or the second edition of Aromatherapy: A Complete Guide to the Healing Art by Kathi Keville and Mindy Green. Both Keville and Erickson are qualified aromatherapists.
Valerie Ann Worwood is a well-respected aromatherapist who has written a number of books. Possibly her most popular book is The Complete Book of Essential Oils and Aromatherapy, which provides more than 600 natural, non-toxic, and fragrant recipes. I particularly like her somewhat more advanced aromatherapy books: The Fragrant Heavens, later republished as Aromatherapy for the Soul, which explores the spiritual and energetic dimensions of aromatherapy, and The Fragrant Mind, which looks at aromatherapy for personality, mind, mood, and emotion.
For using essential oils during pregnancy, see Aromatherapy and Massage for Mother and Baby by Allison England, an aromatherapist with personal experience working with pregnant women and new mothers.
For using essential oils with animals, see Holistic Aromatherapy for Animals by Kristen Leigh Bell.
For a collection of essential oil recipes from a professional, Aromatherapy Recipes for Health and Home is an aromatherapy ebook from Andrea Butje, clinical aromatherapist and founder of the Aromahead Institute. Butje provides a brief introduction to the basics of using and blending essential oils, and then gives you more than 60 aromatherapy recipes for use in the kitchen, living room, and bathroom, plus recipes for skin care, children, and travel. The book is also available as a paperback.
You might also want to take a look at these two inexpensive ebooks from certified clinical aromatherapy Sharon Falsetto: 25 Simple Perfume Recipes with Essential Oils and 25 Basic Aromatherapy Recipes for Beginners.
Another ebook option is The Aromatic Life: Natural Lifestyles Using Essential Oils, compiled by Jen Gallagher, who is a certified aromatherapist in Australia studying for an Advanced Diploma of Aromatic Medicine. This aromatherapy ebook contains eight chapters, two written by Gallagher (one on diffusing and one on beauty and body care) and six written by other aromatherapy users:
Gallagher and the other contributors to this book are users of Young Living essential oils, so some of their recommendations include proprietary blends. This substantial, 135-page ebook is a good choice for anyone using Young Living oils or who wants to learn about using them. (Click here to learn how to buy Young Living essential oils.)
For more advanced information, a good reference book is the Essential Oils Desk Reference.
For information on the chemical composition of essential oils, take a look at Kurt Schnaubelt's Advanced Aromatherapy: The Science of Essential Oil Therapy. Also, Schnaubelt's newer book, The Healing Intelligence of Essential Oils, is a more complete resource with a broader range of technical information and more aromatherapy recipes.
For the healthcare professional or really serious reading, there's Aromatherapy for Health Professionals by Len and Shirley Price. Another important book is the second edition of Essential Oil Safety by Robert Tisserand.
Two other specialized aromatherapy books of interests are Aromatherapy for Healing the Spirit by Gabriel Mojay, which looks at essential oils from the perspective of Traditional Chinese Medicine, and Ayurveda & Aromatherapy by Light and Bryan Miller, which is a guide on how to use essential oils in a manner consistent with Ayurvedic healing.