How Do You Create a Healthy Team Norm?

Teamwork is critical to agile methodologies and our lunch discussion topics show it. The March pub lunch will focus on what healthy team norms are. Team norms can help members understand how to interact with each other and how to conduct the daily business. This can include interpersonal items like respect, agreed tool usage, or company objectives such as time for cross-training and continued learning. What would you consider norms for a "healthy" team? As a team member, what have you experienced that you like (or that didn't work)? As a facilitator, what have you seen work well? How should such a team agreement be manifested and documented? And who should contribute to the content?

Share your experience about teams creating their norms and standards, and listen to others offering their experiences how creating a team agreement can help and how to go about it.