Also known as chapter pedagogy or apparatus, this refers to how you will set up your chapters. You'll want to work out the following elements with your editor:

Each chapter beginning had a picture. The chapter learning points preceded the text.

• Internal Style Devices: Among others, this pertains to use of bold type, bullet points, links to supplemental manuals, numbered lists, graphs and placement of review questions.
• Feature Blocks: This refers to text that is boxed or displayed with highlighted background color. Good examples can be found in the Idiot Guides. In the Complete Idiot's Guide to Meditation for instance, little snips of text called—From A to Om, Bliss Byte and Mindful Minute—appear throughout the book. Pictures and drawings also keep the reader engaged by adding flair and text support.
• Closings- Review questions, summaries, commentaries, links and snap quizzes make up chapter closers.

Consistency rules for chapter structure. When the reader knows he'll see the same set up for each chapter he develops a degree of comfort in the material and confidence with the writer.

In addition to providing a constant throughout your book, the feature blocks, pictures and stories add illumination and enhance the readers understanding of the material. Plus, they make the reading more interesting.

All of this makes it easy for the students to learn. And isn't that why you're writing the book?