Instead of having me try to describe the charter, I thought it would be better to just post a charter template to provide a feeling of what you should be going for. The charter meeting is all about divergent and convergent open discussion. You need to facilitate the discussion. As you use the template you may feel that it was set up as a sales tool. Product management is somewhat a sales role, and your degree of success as a product management team will depend somewhat on your team's leadership...