Here are some of my favorite vendors and websites with useful information.
National Association for Holistic Aromatherapy
This is a member based non-profit association devoted to the holistic integration and education of aromatherapy into a wide range of complementary healthcare practices including self care and home pharmacy. On this site you can find a list of certified Aromatherapists, Approved schools offering Aromatherapy certification at all levels, vendor sponsored resources and other information pertaining to Holistic Aromatherapy.
New York Institute of Aromatic Studies
Purely educational offering free classes and paid certification classes at all levels
Aromahead Institute seeks to make the study and therapeutic use of essential oils widely accessible to casual learners and healing arts professionals around the globe through state-of-the art online study programs. Their evidence based curriculum approach incorporates both intensive science and practical hands-on instruction to support individuals and professionals alike in studying and sharing the many benefits of Aromatherapy. Aromahead offers an excellent free introductory essential oil class along with other free webinars. They also offer Aromatherapy certification classes.
Monterey Bay Spice Company
Selling organic Herbs, Spices, Teas, Oils, and Supplies
Mountain Rose Herbs
Selling organic Herbs, Teas, Oils, Supplies, Books and Supplies
Selling pure organic essential oils, hydrosols, supplies, and recipes. This is an excellent resource for detailed information on individual oils and blends.
Florihana is a family owned distillery, located in France, that produces a wide range of organic aromatherapy products such as essential oils, hydrolats (floral water), vegetables oils and natural/organic cosmetics. They ship to the United States.
From Nature With Love
Offering a variety of premium quality organic, natural and essential personal care ingredients used in skin care, hair care, aromatherapy, massage, spa, herbalism and soap making applications. The also offer packaging, natural bath accessories, equipment and books.