Start with high-confidence training & conditioning books, then narrow by subgenre or adjacent topics.
Nutrition for Sport and Exercise
Marie Dunford, J. Doyle
Science of Swimming
Brett Hawke
Nolan Ryan's Pitcher's Bible
Nolan Ryan, Tom House
Leisure Program Planning and Delivery
Ruth V. Russell, Lynn M. Jamieson
Long-term Athlete Development
Istvan Balyi, Richard Way
Breathing for Warriors
Dr. Belisa Vranich, Brian Sabin
Ballistic
Henry Abbott
Springboard and Platform Diving
Jeff Huber
Pilates and Conditioning for Athletes
Amy Lademann, Rick Lademann
Aerial Adventure Environments
Elizabeth A. Speelman, Mark Wagstaff
The Pilates Edge
Daniel Loigerot, Karrie Adamany
Peak
Dr. Marc Bubbs, Chelsea Green Publishing
Periodization of Strength Training for Sports
Tudor O. Bompa, Carlo Buzzichelli
Essentials of Strength Training and Conditioning
NSCA -National Strength & Conditioning Association, G. Gregory Haff
Developing the Core
Jeffrey M. Willardson
Developing Power
NSCA -National Strength & Conditioning Association, Paul Comfort
High-powered Plyometrics
James Radcliffe, Marcus Mariota
The Climbing Bible: Practical Exercises
Martin MobrĂ¥ten, Stian Christophersen