All Sides of the Story

I'm consolidating some of the information from posts already on this achievement and adding a bit more. If I missed anything, just comment and I'll add it.

Special note that the Duroz and Kolgar part takes 3 weeks to do, and the Tarjin part takes 6 weeks to do. If you're doing the Tarjin part last, the achievement will pop after you listen to Tale of the Weakling

Captain Garrick & Shuja Grimaxe:

1. 
   
2. [quest=66110] or Give Peace a Chance
3. 
   
4. Encroaching Elementals or Encroaching Elementals
5. 
   

/way #2022 76.6 34.6 Captain Garrick & Shuja Grimaxe

Duroz & Kolgar (Takes 3 weeks):

1. 
   
2. Week 1: Untold Regrets. Inside a cave
3. 
   
4. Week 1: Pain Management
5. 
   
6. Week 2: The Bitter End
7. 
   
8. Week 2: Life After Life
9. 
   
10. Week 3: Hollow
11. 
    

/way #2022 57.65 66.96 Duroz & Kolgar (inside cave)
/way #2022 56.80 64.47 Duroz & Kolgar (pools after quest 1 and 2)

Veritistrasz:

1. 
   
2. Stay a While
3. 
   
4. Memories
   
   1. 
      
   2. Begin at [npc=194076] and [spell=383734]
   3. 
      
   4. Listen all stories from Dwarf until Memories appear.
   5. 
      
   
   
5. 
   
6. Memories Revived
   
   1. 
      
   2. Starts from [item=198661]
   3. 
      
   4. [item=198661] is in the Obsidian Throne
   5. 
      
   6. Entrance: /way #2022 27.17, 60.90 Entrance to Obsidian Throne
      Diary: /way #2022 23.0 60.0 Diary
   7. 
      
   
   
7. 
   

/way #2022 57.8 66.8 Veritistrasz

Tarjin the Blind (Takes 6 Weeks):
Weekly Quest to collect 5 [item=199822] which unlocks [spell=388161].

Stories:

1. 
   
2. Week 0: How did you lose your eyesight?
3. 
   
4. Week 0: Why aren't you with the other djaradin?
5. 
   
6. Week 1: Tale of the Outsider
7. 
   
8. Week 2: Tale of the Elders
9. 
   
10. Week 3: Tale of the Warlord
11. 
    
12. Week 4: Tale of the Slumbering
13. 
    
14. Week 5: The Magma Pact
15. 
    
16. Week 6: Tale of the Weakling
17. 
    

/way #2022 16.2 62.6 Tarjin the Blind

Where to Start, Coordinates:
/way #2022 76.6 34.6 Captain Garrick & Shuja Grimaxe
/way #2022 57.65 66.96 Duroz & Kolgar (inside cave)
/way #2022 56.80 64.47 Duroz & Kolgar (pools after quest 1 and 2)
/way #2022 57.8 66.8 Veritistrasz
/way #2022 16.2 62.6 Tarjin the Blind

Information consolidated from:
https://www.wowhead.com/achievement=16406/all-sides-of-the-story#comments:id=5483330 by https://www.wowhead.com/user=Sipder2
All Sides of the Story#comments:id=5487383 by https://www.wowhead.com/user=Taliesen
All Sides of the Story#comments:id=5519196 by https://www.wowhead.com/user=Sharpbladez

Note that the quest line with [npc=196214] takes 6 weeks of collecting skulls to receive story details in piece-meal fashion. Order of the tales:

1. 
   
2. Tale of the Outsider
3. 
   
4. Tale of the Elders
5. 
   
6. Tale of the Warlord
7. 
   
8. Tale of the Slumbering
9. 
   
10. Tale of the Magma Pact
11. 
    
12. Tale of the Weakling
13. 
    

The quest line with [npc=194801] takes 3 weeks - The first week you receive two quests, the second week you receive two quests, and on the third week you will receive a quest that ultimately awards progress for Duroz & Kolgar.

New quests with each of these NPCs resets with the weekly reset.

The [item=198661] item for the All Sides of the Story achievement can be found in the Waking Shores at the coordinates 23, 60. To reach the bookcase where the book is located, you need to go into the Vaults at 27, 61, also in the Waking Shores. Head down the stairs, and then take your first left. Continue until there's a room on your left side again, and enter that room. On the right side, there's a bookcase with an interactable book which starts the Memories Revived quest! I also submitted a screenshot of the book in the bookcase, hope it helps!