I bought this book a few years ago. I have built a BUNCH of stairs and this book would have been handy when I started.
Staircases, Balustrades and Landings
by William P. Spence
It's informative and easy to understand. The illustrations are good and the math is explained well. It also has a good coverage of handrails. You will get an education on the vocabulary of the parts and design elements. Flights and landings are words that have other meanings. Newel posts, winders, skirt boards,, all stair parts.
While it doesn't have detailed architectural drawings and decorative design details, it is perfect for getting a good basic knowledge of staircase design and the sequence of building your own.
Tom in KY, it even has a special chapter on curved and spiral staircases.