Taken from http://www.agileopennorthwest.org/.  I really like these as general principles.

The Five Principles

• Whoever comes is the right people.
• Whatever happens is the only thing that could have.
• Whenever it starts is the right time.
• Whenever it’s over, it’s over.
• Wherever it happens is the right place.

The Law of Personal Mobility

If you find yourself where you can’t learn or contribute, move yourself to a place where you can.