As soon as you start the Chapter look over to the building on the left hand side. You should be bale to see the target on the back wall through the broken windows.
After jumping down to the area below, follow the walls on the left hand side. you will find the poster tucked away in a corner behind several boxes and crates.
Once you have cleared the area jump up to the next balcony area. You should see the poster on your right hand side as you jump up.
After dropping down and lifting the garage door, head up the first set of stairs and turn around. You will see the target right in front of you before the second set of stairs.
At the top of the stairs the door will be blown open, as you head through the door there will be a payphone on your right, the poster is on the left hand side of the doorway.
Follow the hallway and you will exit through a set of double doors to an MG gunner (near where you jumped down a few moments ago). Look behind the left hand side of the door as you exit to collect the next poster.
After destroying thee MG look over the left hand side of the balcony, you should see a garbage truck with the target sitting on top.
Run up towards where the MG gunner's barricade is, then look over the right hand side of the bridge. You will see the target on the right hand side on the wall.
After you see the cut-scene of the barricade being destroyed, walk through but don't jump down. Look over between the air ducts where you have to kill the enemy with the RPG and you should see the target on the building.
Jump down to the area below and run over to the small gap between the two buildings on your left hand side. The post is on the left hand building.