Start with high-confidence acting books, then narrow by subgenre or adjacent topics.
Playing Shakespeare
John Barton
A Practical Handbook for the Actor
Melissa Bruder, Lee Michael Cohn
Thinking Like a Director
Michael Bloom
The Power of the Actor, Revised and Updated
Ivana Chubbuck
The Actor's Audition
David Black
Voice and Speech in the Theatre
J. Clifford Turner, Jane Boston
Acting for Young Actors
Mary Lou Belli, Dinah Lenney
Writing
Robert Emmet Long
Moment Work
Moises Kaufman, Barbara Pitts McAdams
Madly, Deeply
Alan Rickman, Rima Horton
From Word to Play: a Textual Handbook for Actors and Directors
Cicely Berry
Acting Antics
Cindy Schneider
Notes on Directing
Frank Hauser, Russell Reich