My new book, Far Inside The Arduino: Nano Every Supplement is now available on Amazon. https://www.amazon.com/gp/product/B08GFL6VBF. It’s $9.99 as a Kindle E-book, or $11.99 printed. Roughly half the price of the earlier book for the Uno/Mega/Nano but then it doesn’t cover the theory of the interfaces, just how the differ.
Because the Arduino Nano Every has so many features not utilized by the Arduino Library, there is a considerable advantage utilizing the information in this book. The advantage is much greater than that of the earlier book for the Arduino Uno/Mega/Nano. Frankly, considering cost, performance, and ease of use, this is my “go to” Arduino board.