The Fences Note is another of Bill's reminders, on the table in the back room of his safehouse near the pipe he handcuffs Ellie to.
This is the third time this month that infected have piled up against a fence and knocked it down, and Bill writes himself a capitalized order to clear them.
Bill's notes all point the same way: he keeps the town livable by constant upkeep, and the infected keep testing it.
Bill's Map
Bill's Map is Bill's hand-annotated map of Lincoln, on a table with an engine near the door you come in through at his safehouse, right after you meet him.
Bombs Note
The Bombs Note is on a table to the left in the side room off the nave of Bill's church. Go into the room on the right, the one Bill makes clear is not the confessional.
Boy's Diary
The Boy's Diary is on the windowsill of a child's bedroom painted with stripes and cars, upstairs in the second house with the dry pool in the new territory beyond the church graveyard.
Hunters Note
The Hunters Note is a reminder Bill left on a table in the room at the end of the hall upstairs. Leave his safehouse, go up the stairs, turn right and walk to the last room.