The Missions panel show up to 16 currently active missions you have accepted, what type a mission it is, the reputation and influence gain, your payment, the destination and the time in which the mission should be completed. On the left of the panel, two icons indicate the potential Reputation to be gained (+, ++, +++) from the mission and the potential Influence (^, ^^, ^^^).
Missions can be sorted by mission location, mission type, distance to destination and the time left with the four buttons above the list.
On the right side of the panel, clicking on the Set Destination button of a mission will change your current destination in TCE to that mission's location. The Details button brings up the Personal panel to show the details of a mission.