Here is a quick unsorted list of all the memeory piece locations.
Note: Descriptions may be slightly incorrect due to human memory. Forgive me for any troubles.

This is probably the first one you will find. It is in the room with the flashlight on top of a small box tower.

This is probably the second you will find. It is also located in the flashlight room, by two blue tarped pipe stacks near a corner.

This is probably the third one you will find. It is located in the room where you first find pills, after crawling in the vent, at the top of a locker.

This is probably the fourth one you will find. It is located in a hall where you first meet one of the monsters under a desk.

This is probably the fifth one you will find. It is located in the dirt left of when you exit from first meeting the monster.

This is probably the sixth one you will find. It is located in the room Andre was, to the left closest to where you enter, behind a shelf.

This is probably the seventh one you will find. It is in the room opposite of where the sixth one was held, next to some bunk beds.

This is probably the eigth one you will find. It is located in the section where one monster patrols after you enter the room with three monsters, inside a desk in one of the rooms (possibly on the second floor).

This was a short list of all the memory piece locations. I hope you gained at least some help from this short list, as it wasn't very descriptive.
Good luck!