From the overview screen you can see the Top Frame showing your current planet and resources available.
The events portion is particularly useful as it is the only place where you can see all Fleets moving to and from your planets. Friendly fleets are shown in Green and hostile fleets are shown in Red. It shows timers counting down until your fleets reach their destinations. Note that fleets are often shown twice, once for their destination times and again for their return times. The exception for this is deployment missions which have only one destination.
Enemy fleets heading towards your own planets are also (only) shown on this screen. They are shown in red text, with arrival times counting down on the left side of the screen. This information allows you to do things like Fleetsave or other manuvers to lessen the effect of the attack.
By hovering your cursor above the fleet or mission you can get information about the fleet and its cargo. Friendly fleets will always show you the number and types of each ship, as well as cargo load (if any). Enemy fleets will show you information in the tool tip depending on your level of Espionage Technology.
Planet List Edit
This section is divided into two portions. On the left half, there is a large picture of your currently selected planet. On the right side, there will be a list of your planets with thumbnail pictures. Clicking on any of these pictures will select that planet.