When selecting aromatherapy books, 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 aromatherapy expert Kathi Keville offers good, basic information, along with some recipes, but isn't the best written book. Authentic Aromatherapy: Essential Oils and Blends for Health, Beauty, and Home by Sharon Falsetto, a UK-certified aromatherapist, is a better choice for essential oil profiles but doesn't have many recipes.
A nice medium between those two books is The Heart of Aromatherapy by Andrea Butje, a clinical aromatherapist and founder of the Aromahead Institute.
Valerie Ann Worwood is a well-respected aromatherapist who has written a number of aromatherapy books. Possibly her most popular 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.
You might 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 interest are: