Once you have visited the Camera Shop for the first time you can begin collecting photos. Most of these can be acquired only at certain key moments during the game, so if you want to collect them all you'll have to be very careful not to let a photo opportunity pass you by.
Photo #1
Talk to the photographer and agree to have your picture taken. Link poses and pulls a peace sign.
Alternate Photo #1
Answer "No" each time the photographer offers to take your picture.
Photo #2
Take Marin to the cliff at the seaside in the south-west of Koholint to get this picture.
Photo #3
Get this simply by falling into the village well any time when Marin is following you.
Photo #4
Take Marin all the way back to the Flying Rooster memorial.
Photo #5
Look in the (invisible) window on the right-hand side of Old Man Ulrira's house.
Photo #6
Simply leave Madam MeowMeow's house after returning BowWow to get this one.
Photo #7
A photo of a furtive-looking Link skulking out of the Mabe Village shop. Get this by stealing something from the shop.
Photo #8
After getting the Magnifying Glass, go visit the fisherman under the bridge. Talk to him and he'll get a bite. He reels in the cameraman who takes a photo as the fisherman falls in the water.
Photo #9
Go to the seemingly empty house to the north-east of Animal Village after acquiring the Magnifying Glass. You'll discover a hidden Zora there.
Photo #10
Go stand in front of Richard's castle before lowering the drawbridge and Richard will come up saying something about a hunt.
Photo #11
Get this one by examining the ghost's grave after helping him.
Photo #12
Go to the hen house on Tal Tal Heights and walk to the middle of the bridge two screens east of that location.