The How to Make Soap with Milk guide provides step-by-step instructions for making creamy, nourishing soap using milk as a substitute for water in cold process soap recipes. It explains the importance of freezing milk to prevent scorching, details essential safety measures when handling lye, and provides a basic milk soap recipe using olive oil, coconut oil, and castor oil. The guide also offers customization options with different types of milk, explains the effects of gel phase on soap color, and provides tips for achieving the best texture and curing results.