A list of books that have been useful or inspiring to me, and which I often end up referring to in training or coaching sessions:

 

Consulting Mindset and Organisation

Flawless Consulting: A Guide to Getting Your Expertise Used
by Peter Block

The Trusted Advisor
by David H. Maister, Robert Galford, Charles Green

Managing the Professional Service Firm
by David H. Maister

Structured Communications

The Pyramid Principle:Logic in Writing and Thinking
by Barbara Minto

Say it With Presentations, Revised & Expanded: How to Design and Deliver successful Business Presentations
by Gene Zelazny

Say It With Charts: The Executive's Guide to Visual Communication
by Gene Zelazny

The Exceptional Presenter: A Proven Formula to Open Up and Own the Room
by Timothy J. Koegel

The Economist Style Guide
by The Economist

Fowler's Modern English Usage (Re-Revised 3rd Edition)
by R.W. Burchfield

Business Development

Secrets of Great Salespeople: 50 Ways to Sell Business-to-Business
by Jeremy Raymond

Mastering the Complex Sale: How to Compete and Win When the Stakes are High
by Jeff Thull

Book Yourself Solid: The Fastest, Easiest, and Most Reliable System for Getting More Clients Than You Can Handle Even If You Hate Marketing and Selling
by Michael Port

Writing Winning Business Proposals: Your Guide to Landing the Client, Making the Sale and Persuading the Boss
by Richard C. Freed, Joe Romano

Behaviour and Performance

Coaching for Performance: GROWing Human Potential and Purpose - the Principles and Practice of Coaching and Leadership (4th Edition) (People Skills for Professionals)
by John Whitmore