There are two categories of ingredients that are commonly used to scent soap: essential oils and fragrance oils. Each has its benefits and disadvantages.
Essential Oils and Fragrance oils for soap making
Essential Oil Blends for Soap Making — The Essential Oil Company
Five more essential oils that are perfect for use in cold process soap making
Soap Making: Essential Oils or Fragrance Oils? — The Essential Oil Company
Soap Making — The Essential Oil Company
14 x10ml Aromatherapy Essential Oil Large Pure & Therapeutic Grade
Lavender 40/42 Essential Oil – Arizona Soap Supply
Essential Oils vs. Fragrance Oils - Soap Queen
My Top Three Essential Oils For Soap Making — Ruth Romano
Essential Oils
Soap Making — The Essential Oil Company
Essential Oils For Soap Making
PHATOIL 9PCS Essential Oils Gift Set, 10ml/0.33fl.oz Scented Oils for Soap, Candle Making, Premium Quality Essential Oils for Diffuser, Humidifier, Massage : Health & Household