If you can't find certain things for soapmaking in your town, like lye, certain essential oils, and powedered color, for instance, the best way to do is order in bulk online. However, lye (sodium hydroxide) is considered a "dangerous good" and cannot be shipped by mail within the USA. I have to drive all the way to the next city over to buy my lye because of the methamphetamine problem here. Lye is a key ingredient in it, apparently. Look below for some good suppliers.
Links to other sites on the Web
Cranberry Lane
Majestic Mountain Sage
The Soap Saloon
Herbal Accents
Soap and Soap Supplies.com
Esoap Supplies