Cicely Berry, Voice Director of the Royal Shakespeare Company, is world-famous for her voice teaching. The Actor and the Text is her classic book, distilled from years of working with actors of the highest calibre.
Read a long time back, so sketchy review. This is an extremely in-depth exploration of how an actor can get the most out of a text. It focuses mostly on Shakespeare because he has it all going on, but Berry's techniques are plainly universally applicable.
Berry's great strength is in discovering the value and effect of every detail of the language: the implied pause in the middle of a line, the insertion or omission of a syllable in the pentameter. She provides exercises - marching out the line, passing the dialogue around actors in alternating words - to help the serious actor unearth the potential in the text. I read it merely as an occasional narrator of audio books, but I found myself underlining something on almost every page.
This is not a book to read out of casual interest and can be hard-going; but it's surely invaluable to a professional actor.
A guide to exploring the written and spoken styles of theatre and language and how to approach them as a performer. Includes warm-up exercises and rehearsal techniques.