The Oscorp Sign: At the start of "Raid on Oscorp" you'll be given this assignment on your way to Oscorp Tower. Just snap the pic before you enter the building to begin the mission.
Daily Bugle Sign: At the start of the "No One is Safe" mission, you'll start right near the Daily Bugle building and can see it clearly in the night sky. If you miss it however, you can find the building located at the position on the map above.
Comic Stand: For this photo, all you need to do is snap a shot of Stan's comic Shop, which you can easily find by going to the comic book marker on the city map.
The Fisk Tower: The Fisk Tower is located to the southwest of the city and the sign that needs to be snapped is on the ground floor. If you have troubles locating the building, just go to the location on the map above.
The Wake: At the beginning of "The Green Goblin!" mission, you'll receive the assignment to snag this photo of the nightclub sign. The sign is found on the roof of the building located on the image above. It can be tough to see if you’re running around on the ground, so get airborne and you will see the sign with it’s large red and white letters much easier.