The Engineer's Manual is a book added by Immersive Engineering. It is an in-game guide to the mod and it's mechanics.
The GUI interface includes a table of contents separated by 6 sections per default: "UPDATE NEWS!", "Overview and Resources", "Construction", "Power, wires, generators", "Tools and Simple Machines" and "Heavy Machines". Further sections may be added due to crossmod integration and addons. Each section has multiple entries, and each entry has one or more pages. Pages can include text, images, crafting recipes and multi-block models that give information.
NOTE MAY CRASH IN CURRENT VERSION.