Thom Roach shares with us in this blog post the metrics that he includes in iteration summary reports. The three main statistics he uses are Iteration Statistics summary, Iteration Cumulative Flow and Team Velocity Chart.
The Iteration Statistics Summary displays three sections of data (user stories, user stories points and velocity) at three different stage of the iteration (predicted before planning, planning and actual). The Iteration Cumulative Flow Diagram shows the state of the committed stories each day of the iteration. The Team Velocity Chart displays the normalized velocity for a series of iterations. By dividing the total earned points by the number of man-days, the chart shows if the team is earning a consistent velocity over time for the people on the team.