Ok i got a ship that has a planet scanner on it. I've been searching the menu's everywhere but I can't find the command to scan a planet. So how do i do it?

You have to be in the sector of the planet you want to scan. Hit L to land, at that time it will display all the AVAILABLE planet info. I say available because if you scan a shielded planet you will see nothing but the planet number and SHIELDED.