Start with high-confidence pilates books, then narrow by subgenre or adjacent topics.
Yogilates(r)
Jonathan Urla
The Complete Book of Pilates for Men
Daniel Lyon
The Pilates Body, Revised and Expanded Edition
Brooke Siler
Science of Pilates
Tracy Ward
The Pilates Body
Your Water Workout
Dr. Jane Katz, Jane Katz
Chair Pilates and Yoga
Harri Angell
Fusion Workouts
Helen Vanderburg
Pilates and Conditioning for Athletes
Amy Lademann, Rick Lademann
Pilates
Rael Isacowitz
Osteo Pilates
Karena Thek Lineback
Ellie Herman's Pilates Props Workbook
Ellie Herman
Ellie Herman's Pilates Workbook on the Ball
The Pilates Edge
Daniel Loigerot, Karrie Adamany
Core Awareness, Revised Edition
Liz Koch
The Women's Health Big Book of Pilates
Brooke Siler, Editors of Women's Health Maga
RAPilates
Chuck D, Kathy Lopez