My gal Marie Gale recently published a book about labeling.
The book got a great review today on About.com from the Candles and Soap About.com editor, David Fisher.
The book is a very comprehensive and helpful guide to how to label soap and cosmetics, for the handcrafted soapmaker. Big corporations making soap (usually making detergents, not actually soaps at all), have teams of lawyers on retainer or in-house to help them cope with the many requirements of labeling soaps and cosmetics. There are so many regulations that it is quite possible to be in non-compliance with one or more of the regulations, despite one's best intentions, which noncompliance can put the small soap maker at legal risk.
So Marie's book, while not a replacement for a lawyer's advice, will certainly help many small soapmakers become conversant with and more likely to be compliant with the rules and regulations. These rules and regs are buried in among other non-applicable laws and regulations, so Marie dug them out and organized them by industry and state. It's a very useful book. She has been getting and delivering many orders for the book since its first publication in May of this year (2007).
There was also a very good review of Marie's book in the Saponifier magazine, which she will have up on her website soon. You can only read Saponifier Magazine online if you have a subscription, so there's no link directly to the article about her book.