Good to see you! Have we met before?

Ah, yes, of course—here is the first clue to filling the map—rows 16 and 17 are as follows:

Now, every clue you find hereafter will indicate the relevant row(s) of the map, and exactly how to shade it.

But the clues won't always take the form of images.

Also, 1 is black.

Now go to the root to proceed onward.