When something inspires me, I can't help but share it with others - to the point where I've felt the need to qualify my recommendations by saying, "I swear I'm not getting paid a commission on this..."!
Here are some of the resources that have inspired me over the years:
Getting to Yes by Roger Fisher, William Ury & Bruce Patton
Difficult Conversations by Douglas Stone, Bruce Patton & Sheila Heen
Influence: The Psychology of Persuasion by Robert Cialdini
The Trusted Advisor by David H Maister, Charles H Green & Robert M Galford
Action Inquiry by Bill Torbert & Associates
The Practice of Adaptive Leadership by Ronald Heifetz, Alexander Grashow & Marty Linsky
Coaching to the Human Soul (Vol 1-3) by Alan Sieler
Drive by Daniel H Pink
The Unopened Gift by Dan Newby & Lucy Núñez
The Language of Emotions by Karla McLaren
Finding Your Own North Star, by Martha Beck
Passages: Predictable Crises of Adult Life, by Gail Sheehy
The Heroine's Journey, by Maureen Murdock
"Getting Out of Your Own Way"
I've also created a recommended reading list for the GOOYOW workshop, which you can download here.