Okay, it's not an icon. It says
Library at the top left of iTunes.
Just drag the music or the folders the music is in to it.
I still have to go through each and every folder to find the songs I added just so I can drag it over.
Why?
Drag the _top level folder_ to the
Library. This would be the *iTunes music folder*, where you seem to be putting your music.
Better yet, as has been posted a few times,
File -> *Add folder to library* and pick the top level folder. You do not need to select the lowest level folder.
Do this to make it easier.
Open iTunes prefs -> Advanced.
Tick *Copy files to iTunes music folder when adding to library*.
Tick *Keep iTunes music folder organized*.
When you get new music, dump it into a folder on the desktop. Don't worry about sorting it.
Then File -> Add folder to library and select this folder./
Once iTunes is finished adding the music, you can delete the files in the folder on the desktop. iTunes has copied them into the iTunes music folder.