Duly noted and you make a good case. I agree in part... there are problems with some of the recipes and old school techniques. However, much of the content is still valuable today and worth the price if you can find them.I am going to have to respectfully disagree on using books to learn soapmaking. Many libraries' soapmaking book list is both extremely small and extremely old. We've learned so much more now than is reflected in some of those books.
Here are my recommendations for good reads that are on my reference shelf:
Best Books & Reference Materials for CP Soap
Susan Miller Cavitch's recipes have 10% SF and GSE (Grapefruit Seed Extract) for its antioxidant benefit. Both of those are no longer recommended. GSE is not only hard to find but expensive as well and has been proven to be ineffective for preventing rancidity. However, the bulk of the content is solid and well worth adding to a soaper's reference library.
Soap Naturally by Patricia Garzena and Marina Tadiello is the best all around reference for soap making to date and covers other bath & body products as well.
Making Soap and Scents by Catherine Bardey was the first book I bought when I found it in the bargain bin at Barnes & Noble. It's a small book. Has few soap recipes, but the rest of the info is well organized and relevant today. I used her recipe and technique to successfully make transparent soap -- one of the first soaps I ever made. Luv it!
Making Liquid Soaps by Catherine Failor has a wealth of science-based information on the subject although her technique is passé and the content is confusing and poorly organized. I still refer to it for troubleshooting batches that have gone awry.
Handcrafted Soap by Delores Boone - Although the recipes are wonky due to proof reading errors, the beautiful pictures are outstanding for displaying the equipment we use, how to use it and lovely soaps to inspire you. The charts and glossary are a quick and easy reference to calculating lye & water by hand; the properties of various oils, fats & butters; and an extensive list of essential oils -- featuring "Characteristics", "Perfume Notes" and "Blends Well With".
The best thing about books is, to my mind at least, if you're off-grid or do not have access to the internet for any reason, you can still learn to make soap -- all by yourself -- and enjoy it the fruits of your labors.