One of the best introductions to NVC is this lecture from the founder Marshall Rosenberg. When I commuted I must have listened to it 4+ times as there is always something new to learn from it.
NVC Marshall Rosenberg — San Francisco Workshop — FULL ENGLISH SUBTITLES TRANSCRIPTION
Or (same workshop)
Nonviolent Communication — San Francisco Lecture Workshop — Marshall Rosenberg *Synced sound*
The basic framework of NVC is OFNR — Observations, Feelings, Needs, Requests.
People often refer to and use feelings and needs lists:
https://www.cnvc.org/training/resource/feelings-inventory
https://www.cnvc.org/training/resource/needs-inventory
