Making a (digital) book of Solarus is really a fantastic idea.
Like Christopho already mentioned the book needs only a few chunks.
Here is my idea of the contents:
- Chapter 1: Introduction
- 1. What is Solarus?
- 2. How to install?
- 3. Starting your first project
- 4. Saving and loading projects
- 5. Explain what can be found in the editor (like the map editor, sprite editor, dialog editor etc...)
No details of how building works yet, only where to find them. Also some explanation of the UI (zooming, grid, options-menu, etc..).
- Chapter 2: Basic Mapping
- Explain chapter 2 - 9 of the video tutorials here
- Chapter 3: Advanced Mapping
- Explain chapter 10 - 17 + 19 of the video tutorials here
- Chapter 4: Lua Scripting
- Short basic Lua scripting tutorial
- -- Explain chapter 18, 20 and 22 of the video tutorials here
- Advanced environments (screen overlays, weather effects, etc..)
- Ingame events and story chapters (incl camera movements etc..)
- Advanced enemies and bosses
- Creating custom equipment and weapons
- much more...
- Chapter 5: User Interface
- 1. Title screen
- 2. Ingame UI
- 3. Setup game controls
- 4. Ingame options UI
- 5. World map
- 6. Credits screen
- Chapter 6: Distribution of your game
- Explain chapter 24 of the video tutorials here
- Info on licensing (disclaimer info in case of Zelda content usage for example)
And i'd like to mention. If you need help with graphics or something I can support on that. And if you are using Adobe Indesign i can help too. For my job i am actually working with the Adobe suite software, so no problem with that.

Edit: Chapter 4 and 5 switched as suggested by Christopho.