How to get along

As we all know, Harmony in the Sangha is one of the most important attributes of the practicing community which necessarily live and work together. Yet, it is almost inevitable for people - imperfect as we are - to be drawn into squabbles and/or unwittingly hurt one another's feelings in our daily interactions (or non-interactions) with one another. Association with the enemy, as it turns out, is one of the 8 Dukkha's expounded by the Buddha. So: What are the Buddha's advice for people who cannot get along? How should people resolve conflicts when they arise? What should you do to protect yourself if you were deeply hurt by someone close to you?