Getting Started
The guide is based on the Modonomicon version for Minecraft 1.21.1. If you are using an older version, some of the features might not exist yet, and the sample content might not work yet. You can check out the datagen of branches for older Minecraft versions of Occultism or Theurgy for examples on how to use modonomicon.
Modonomicon uses both resources (translation files) and data (page definitions). If you want to live-reload your changes run /modonomicon reload to reload both resource- and datapacks.
This of course requires the changed files to be in the correct data/resource pack locations for minecraft to load.
The easiest way to get started is to follow the step by step guide Step by Step with Datagen. This guide uses datagen, a minecraft development feature, so it assumes that you know how to set up a mod project in either forge, neoforge or fabric.
Even for modpack creators it is recommended to follow this process. Datagen is a much more convenient way to create books and ensure they do not have errors that might keep them from loading or from working in game.
Manually creating books
It is not recommended to manually create books. It is much more convenient and error-free to use datagen. JSON is not a great format for text editing, and can be annoying to properly format text.
If you instead want to manually create a book by creating and editing JSON files directly, follow Step by Step Guide for a Book via Datapack.