Start with high-confidence business writing books, then narrow by subgenre or adjacent topics.
Power Presentations
Marjorie Brody, Shawn Kent
Steal the Show
Michael Port
Writing for Busy Readers
Todd Rogers, Jessica Lasky-Fink
Secrets of Dynamic Communications
Ken Davis, Michael Hyatt
Simply Said
Jay Sullivan
Everybody Writes
Ann Handley
Talk Like TED
Carmine Gallo
Develop Your Presentation Skills
Theo Theobald
Smart Brevity
Jim VandeHei, Mike Allen
The Story Factor
Annette Simmons, Basic Books
Show and Tell
Dan Roam
Winning the Room
Jonathan Pease, Grant Cartwright
Pitch
Danny Fontaine