For all you explorers out there, I want to point you to Captains Log.
Its a tool that allows you to keep track of everything that you scanned on your exploration missions, and can give you a rough estimate of your earnings (not including First Discovery bonuses).
It has an overlay mode so if you play ED in Window or Borderless, it puts a button on the Top Left. Click and it expands for you to enter your data. Like all good programs, you have to enable Verbose Logging in your AppConfig file, but then it will read each jump and you just click on the Star Types, the Planet types, and voila! Everything tracked.
I was using it on my last voyage out, but back then you had to manually select the planet type from a dropdown. Now you just click click click. See the homepage for more info or the FD Forum Thread.
The homepage for the Project it here: http://scarygliders.net/captains-log/
And the FD Thread can be found here: https://forums.frontier.co.uk/showthread.php?t=155545