Easily the best calligraphy manual I've come across. The book teaches not only the basics of the lettering styles, but the finer points, with explicit instruction in the small details that make a hand look right. You're never left copying the same letter over 25 times and wondering why yours doesn't look like the sample. If a curve is supposed to meet an upright at a specific point, the book says so, with illustrations and visualizations to help you internalize the style. It's priceless for beginners like me, who haven't learned how to "see" new alphabets.
It's also priceless for people who find that in the absence of clear instructions to the contrary, their writing reverts to however they normally form letters. I've been having a heck of a time learning calligraphy for that exact reason, but just a week with this book had me writing a presentable Italic hand--practically from scratch.
Although the book proceeds through four different hands, you don't need to do all four in order. I skimmed the start of the book, then jumped straight into Italic, the last hand in the book, and had no trouble understanding the lessons.
This book is also a seriously badass display of calligraphy. The author wrote the entire book by hand. The entire book. The lessons, the preface, the title page, the frontispiece, the copyright page. She wrote the copyright page by hand.
In the pre-digital-correction era.
With a dip pen.
I recommend this book to beginners, to more advanced calligraphers who want to master a specific hand or who want to learn to analyze styles, and to anyone who wants to see what a book looks like when a talented calligrapher creates it start to finish.