Below is an overview of the core technical content usually found in such a manual, which you can use as a template or draft for your own text.

Distinction between Sawn Lumber (standard mill products) and Glulam (layers of wood bonded with adhesives for higher strength and longer spans). 2. Structural Design Principles

Timber Design - Timber Construction Manual - Wiley Online Library

To build effectively with wood, a manual first addresses its natural characteristics:

Structural evaluation, including deflection and ponding.

Understanding wood anatomy, including specific gravity and moisture content, which directly affects structural performance.