Henning Nelms's 1969 "Magic and Showmanship: A Handbook for Conjurers" is a classic of the genre, a book whose auction price spiralled out of control until it was reprinted in a fine facisimile edition by Dover Books in 2000. I discovered the book thanks to James D Macdonald, who uses it as a teaching aid in the Viable Paradise science fiction writing workshop, held annually on Martha's Vineyard.
Nelms was a conjurer who doubled as a stage-director of serious plays, and in Magic and Showmanship, he fused these two disciplines in a single coherent whole, explaining the business of stagecraft, acting, storytelling, costuming, posture, body-language and the thousand tiny disciplines of the stage for magicians, showing them how to turn the "tricks" they performed into bona fide illusions that caused the audience to suspend their disbelief long enough to believe that they were witnessing magic, not trickery.
Nelms accomplishes this by means of detailed descriptions for dozens of illusions, building on them to illustrate each of his points clearly and forcefully. There's plenty to be learned here for anyone who seeks to entertain and interest the public, from speakers to musicians to dancers to writers who give readings of their work.
But that's not why Macdonald recommends this book to his writing-students. Magic and Showmanship is a detailed dissection of stories and entertainment and suspension of disbelief, three key arts of any fiction writer (and they are especially important to science fiction and fantasy writers).
Opening Magic and Showmanship to practically any page yields real insight that can be applied to fiction composition. My copy just fell open on page 64, the middle of the chapter on "Making the Most of Assistants," and this passage leapt out at me:
Stars shine by contrast. Audiences realize that you deserve no credit for outshining a waitress-assistant. The stronger the girl is, the more credit you get for remaining the star. Jack Benny summed this up in a sentence. Someone asked him why he let Rochester steal his scenes. Benny replied, "I'd much rather have him steal my scenes than someone else's."
Many's the writer who can't bear to let his characters outshine his prose -- just when the character is going through her most transformational, difficult moment, the writer is struck by an irresistible urge to throw in a bit of verbal pyrotechnics, to highlight this really smart little turning point the story is going through, when really, this is the character's moment, not the writer's.
Magic and Showmanship is a veritable grimoire of writerly spells and advice -- and it doesn't hurt that the nominal subject, stage conjuring, is a fascinating art all its own, and reading about the theory and practice of it is interesting in its own right. Parts of Magic and Showmanship read like "How to Win Friends and Influence People," and parts of it read like a text on neurolinguistic programming, because both are focused on persuasion, on directing attention, on convincing strangers and friends (and the line-drawing diagrams in Magic and Showmanship are wonderful examples of the illustrative style of the late 60s, instantly recognizable to anyone who's ever stared in wonder and horror at a 60s-era text on posture and deportment, cooking, kung-fu, or any other physical discipline). But Magic and Showmanship transcends hokey advice books and really shines as a text that can be read on many levels, and many times.