Communication Books
Messages is one of the best books I have found in terms of all around thinking about communication. It is not a book on public speaking, rather the focus is on one on one communication.
The Harvard Business Review’s “On Communication” book has great articles on business communications.
Confidence Books
These books are not about communication. They are about confidence. Clearly your internal confidence affects how you communicate so there is a connection.
Power Books
Persuasion Books
Intelligence Approach to Communication