Windmill Operation is a book found in Dishonored 2.
Section 21 - Regular Maintenance
1) Check wind speed. Windmill will only turn with sufficient wind.
2) Danger! High wind may overcharge security systems. (See Appendix, Wall of Light.)
3) Ensure gear works are free of debris.
4) Oil mechanism in accordance with schedule. (See Section 30.)
6) During emergency, disengage windmill using lever, located on "maintenance platform".
7) With windmill disengaged, check wooden blades for cracking or loose supports.
8) Wax wooden blades in accordance with schedule. (See Section 30.)
9) Periodically, gears, blades, and other parts must be repaired or replaced, as specified in Section 10.
This book can be found in the sewers at the very beginning of the mission Dust District.