A treasure trove of great anecdotes.
Just one example:
A few weeks before the launch, the Navigator Command Module Pilot, Jim Lovell, spent a few hours practicing on the earth-horizon sextant simulator at MIT. He consistently identified the “horizon” about 20 miles above the real horizon. Great! Jim Lovell could be calibrated and his bias number loaded in the flight computer.
In the same vein as this article, I am always deeply moved watching Dr. William Widnall's lecture on Apollo's guidance, navigation, and control: