There are tons of notes, clues, and ephemera scattered throughout RE:7, but these are the ones that count toward the Devil Is In The Details achievement. You can always check which ones you've got (and thus, which ones you need) by bringing up the objectives screen ([V]) and tabbing over to Files ([Q]).
Prologue and Guest House
1. Email From Mia: You start the game with this in your inventory. Inspect it to add it to your files
2. List of Names (Front): On the table with the Bolt Cutters, pick up and read the note.
3. List of Names (Back): Flip that same note over to read the back.
4. Home-Improvement Store Receipt: In the dining rooom where you wake up, tacked up to the right of the kitchen counter.
5. Newspaper Article - Missing People: Atop a stack of newspapers in the den, next to the dining room.
6. Newspaper Article - Over 20 Missing: On a table in the Main Hall, nearish the clock.
7. Jack's Journal - In a drawer in the second floor Rec Room.
8. Jack's Memo - Also in the Rec Room, on a table near the outside door.
9. Travis' Memo (Front) - In a drawer in the save room nearest the Scorpion door.
10. Travis' Memo (Back) - The other side of that same Memo. If 'memo' is really the right word.
11. Incinerator Room Memo - On the wall to the right as you enter the incinerator room, above the sink.
12. Memo About Relief - In Grandma's Room (past the Scorpion Door in the Rec Room, to your left as you enter).
13. Doctor's Letter - Also in Grandma's Room, in the drawer of an endtable to the right of the door
14. Zoe's Investigation Notes - On the bulletin board in Zoe's Trailer.
15. Marguerite's Warning: Tacked up next to the Crow Door which leads to the Altar.
16. Serum Documentation: Past the Crow Door, inside the lid of the mysterious case.
17. Marguerite's Notebook: Still in Old House 2F, next to the piano in small room with the tiny effigy.
18. Memo on Deputy's Head: In the fridge in Zoe's Trailer, on the back of the head.
Main House Revisited
19. Lucas' Journal: On the desk in Lucas' childhood bedroom.
20. Torn Page from Journal: On the other desk in Lucas' childhood bedroom.
21. Clock Memo: In the Master Bedroom, taped to a globe next the puzzle clock on the beside table.
22. Memo on Burnt Corpse: After the fight with the Fat Molded in the Barn, find this on the final remains of Clancy Javis.
23. Jim's Letter: First floor Bunk Room, corner bed.
24. Giovanni's Will: On a desk in a room in the southeast corner of the first floor.
25. Orders: In the Guest Room, where the video flashback starts. You can read them then or in the present.
26. Mechanic's Memo: In the elevator, taped up next to the empty fuse and cable slots.
27. Tattered Secret Document: In the present, at the spot where Alan snuffed it, read the lid of the case
28. E-Necrotoxin Report: In the underground lab, inside the lid of the the case where you obtain the necrotoxin syringe.
29. Infection Report: Also in the lab, on the desk to you right as you enter.
30. Email Log: Also in the lab, rad all the pages on the laptop.
31. R&D Report 1 of 2: Also in the lab, behind the necrotoxin case.
32. R&D Report 2 of 2: Last one in the lab, and in the game, on another desk right of the necrotoxin.