The document discusses guilds, which are designed communities of organisms grouped together to mutually benefit each other. It provides examples of different types of plants and organisms that can be included in a guild, such as nitrogen fixers, perennial herbs, fungi, and animals. It also discusses how to design guilds by focusing on one plant's needs initially, connecting other plants that have direct or indirect relationships, and planning for the guild's future succession. Specific plant families and examples of good combinations and things to avoid are also outlined.