Reading is essential to learning. Knowledge is truly power. It is also very important to read multiple views, and not just from one source, so that you can make a decision for yourself, and do your own testing on what is best.
Here are some must read books:
"Building the 95mph Body" - Ben Brewster, Tread Athletics
"Building the 95 MPH Body is one of the most comprehensive resources available on the topic of building pitching-specific strength, muscle, power, and how to throw harder"
"Hacking the Kinetic Chain" - Driveline Baseball
"Hacking The Kinetic Chain is the complete resource for developing high-velocity pitchers. This training manual and digital library is an integrated guide to strength development and pitching training."
“High Level Throwing” – Austin Wasserman, Wasserman Strength
“The High Level Throwing: Baseball Edition E-Book has over 70 instructional videos on baseball throwing mechanics and the following components:
Throwing Patterns by Position
Jaeger Sports J-Band Series
Long Toss Protocols
Post Throwing Stretches/Soft Tissue Work!
Discount Codes to DriveLine Baseball’s Weighted Ball System & Books"
Websites with tons of good articles: