See for a more complete listing.

Nonviolent Communication: A Language of Life by Marshall B. Rosenberg, Ph.D. The classic. We use this as our introductory text.
Nonviolent Communication Companion Workbook: A Practical Guide for Individual, Group or Classroom Study, by Lucy Leu. The study guide for the classic.
Speak Peace in a World of Conflict: What You Say Next Will Change Your World by Marshall B. Rosenberg, Ph. D. NVC introduction with emphasis on social change.
Parenting from Your Heart by Inbal Kashtan. A small booklet on NVC for parenting– just right for busy parents to get a taste of this approach.
Don’t Be Nice, Be Real by Kelly Bryson. Intermediate NVC; funny and insightful.
Peaceful Living: Daily Meditations for Living with Love, Healing and Compassion by Mary Mackenzie. Learn NVC one meditation at a time, one day at a time.