When we organize medium to large size projects we like to create two main committees to ensure the success of the project.  The Project Leadership committee typically includes the IT Leader, the Project Champion (non-IT), and the project manager.  This committee meets regularly, at least 3 hours a week.  This group is charged with:

• Tracking the project plan, taking corrective action where necessary
• Tracking the budget
• Reviewing the issues list
• Planning what updates should be communicated to various audiences
• Summarize all of this in a regular status report

The Project Oversight Committee is comprised of the Project Leadership team and senior leaders with accountability for the success of the project.  It is their job to:

• Regularly review the project controls
• Resolve issues that require senior leader decision making
• Sign off on any decisions that have a significant impact on the goals of the project
• Keep the project leadership team focused on achieving the project goals

This structure has worked well for me and I recommend using this approach as a starting point for your project governance.