Bigger is Better

This list focuses on getting the Garrison to level 2 as quickly as possible without doing any overhead quests. There's 2 Bonus quests that don't take any effort and should be done for extra rewards. The optionals are only interesting if you want the follower, and takes probably 15 minutes additionally to the rest of the quests.

After completing the initial Garrison chain and rescuing Olin, follow the following quests.

1. 
   
2. Mission Probable
3. 
   
4. Den of Wolves
5. 
   
6. Rally the Frostwolves
7. 
   
8. Gormaul Tower
9. 
   
10. (Bonus) Honor Has Its Rewards
11. 
    
12. These Colors Don't Run
13. 
    
14. Deeds Left Undone
15. 
    
16. Great Balls of Fire!
17. 
    
18. The Butcher of Bladespire
19. 
    
20. Armed and Dangerous
21. 
    
22. To the Slaughter
23. 
    
24. Last Steps
25. 
    
26. Moving In
27. 
    
28. Save Wolf Home
29. 
    
30. Free Our Brothers and Sisters
31. 
    
32. The Farseer
33. 
    
34. Pool of Visions
35. 
    
36. Back to Bladespire Citadel
37. 
    
38. (Optional to get Mulverick as a follwer)
    1. 
       
    2. Slavery and Strife
    3. 
       
    4. Mulverick's Plight
    5. 
       
    6. Mulverick's Offer of Service
    7. 
       
    8. The Slavemaster's Demise
    9. 
       
39. 
    
40. Securing the South
41. 
    
42. They Who Held Fast
43. 
    
44. Into the Boneslag
45. 
    
46. (Bonus) Of Fire and Thunder
47. 
    
48. (Optional to get Dagg, Shadow Hunter Rala, Gronnstalker Rokash and Weaponsmith Na'Shra as follower *see note below)
    1. 
       
    2. Frosted Fury
    3. 
       
    4. WANTED: Grondo's Bounty
    5. 
       
    6. We Be Needin' Supplies
    7. 
       
    8. Poulticide
    9. 
       
    10. Lurkers
    11. 
        
    12. The Real Prey
    13. 
        
    14. Oath of Shadow Hunter Rala
    15. 
        
    16. Only the Winner
    17. 
        
    18. Defection of Gronnstalker Rokash
    19. 
        
    20. Smeltcraft
    21. 
        
    22. Blood Oath of Na'Shra
    23. 
        
49. 
    
50. Moving Target
51. 
    
52. The Strength of Our Bonds
53. 
    
54. Where's My Wolf?!
55. 
    
56. Free Dagg from his cage!
57. 
    
58. Enfilade
59. 
    
60. The Master Siegesmith
61. 
    
62. Return to the Pack
63. 
    
64. Bigger is Better
65. 
    
66. (Optional) Services of Dagg
67. 
    

Note:
Just before doing Moving Target, you will be sent very closely to your garrison and it probably is a wise idea to head into the garrison instead, do your profession quest and setup the small plot if possible. If you also want to get extra followers, pickup and do We Be Needin' Supplies WANTED: Grondo's Bounty which will lead you to an extra flight path and a small quest hub with Shadow Hunter Rala. Dagg is nearby in crate in Daggermaw Ravine (39,27). After freeing Dagg, do the quests to get Rala and then head to 58,31 to do a quest for Gronnstalker Rokash. It's quite possible that while doing quests for Mala, you end up next to Rokash and it's okay to do his quest right then. Finally head over to Na'Shra (65,40) and do a quest for her. Either Hearth to your Garrison or walk down to continue with Moving Target.

Level 2 garrison if you have too many chars like I do. I didn't bother with side quests.
Finished it at 91, do not have to be level 92 (@kaimox)

01.Den of Wolves fly to Wor'gol
02.Rally the Frostwolves + Honor has its rewards (gives you unmounted movement speed 30% in Frostfire ridge and get it before turning in Rally the Frostwolves )
03.Gormaul tower
04.These colors don't run (Can run forward to turn it in without waiting for Thrall to do his magic thing)
05.Deeds Left Undone
06.Great Balls of Fire
07.The butcher of bladespire (Dorogg usualy drops items for profession advancement)
08. Armed and Dangerous + To the slaughter
09.Last steps (click ladder/chain)
10.Moving in mount frostwolf after talking to Durotan)
11. Save Wolf home + Free our Brothers and Sisters (together)
12.The Farseer In cave
13.Pool of Visions
14.Back to Bladespire Citadel
15.Ga'nar's Vengeance
16.Let the hunt begin (talk to Ligra before continuing then Ga'nar on next step)
17.They Rely on Numbers + Leave Nothing Behind
18.Wrath of Gronn ( u get it if u finished They Rely on Numbers)
19.The Eldest
20.To the garrison Turn in to Durotan
21.Bigger is Better Talk to Gazlowe and tada. Level 2 garrison.

I was able to get this quest at lvl 91 after completing Return to the Pack. That quest was available after completion of Enfilade. This follows on from the Securing the South given by Durotan, which quest sends you to Stonefang Outpost. And he gives that after you have completed the Wor'gol quest line starting with Save Wolf Home.