Here are some books we recommend
Facilitation & Retrospectives
Kaner, Sam et al., The Facilitator's Guide to Participatory Decision-Making, New Society Publishers 1996
Kerth, Norm, Project Retrospectives: A Handbook for Team Reviews, Dorset House 2001
Stanfield, R. Brian, The Art of Focused Conversation: 100 Ways to Access Group Wisdom in the Workplace (ICA), New Society Publishers 2000
Negotiation
Fisher, Roger, and William Ury, Getting to Yes, Penguin Books 1991
Stone, Douglas, et al., Difficult Conversations. How to discuss what matters most, Penguin Books 2000
Cultural Diversity
Nisbett, Richard E., The Geography of Thought: How Asians and Westerners Think Differently ...and Why, Free Press 2003
Levine, Robert V., A Geography of Time: The Temporal Misadventures of a Social Psychologist, or How Every Culture Keeps Time Just a Little Bit Differently, Oneworld Publications 2006
Social Complexity
Arrow, Holly, et al., Small Groups as Complex Systems, Sage Publications, Inc., 2000
Olson, Edwin E., and Glenda H. Eoyang, Facilitating Organization Change - Lessons from Complexity Science, Jossey-Bass 2001
Stacey, Ralph D., Complex Responsive Processes in Organizations. Learning and Knowledge Creation, Routledge 2001
Sense-making
Dervin, Brenda, Sense-Making METHODOLOGY Reader, Hampton Press 2003
Kurtz, Cynthia, and David Snowden, The new dynamics of strategy: Sense-making in a complex and complicated world, IBM Systems Journal, Vol 42, No. 3, 2003
Snowden, David, Multi-ontology Sense-making: a new simplicity in decision making, Management Today Yearbook 2005
Weick, Karl, Sensemaking in Organizations, Sage Publications 1995
Weick, Karl, Managing the Unexpected. Assuring High Performance in an Age of Complexity, Jossey-Bass 2001
Metaphor
Kittay, Eva, Metaphor: Its Cognitive Force and Linguistic Structure, Oxford University Press 1990
Lakoff, George, and Mark Johnson, Metaphors we live by, University of Chicago Press 2003