[Note: steps 1-7 can be done in any order]
1- Find the Tidal Class Rune Stone (near the Waterfall at the lake)
Headmaster: "Tidal Class dragons live in or near the water. The Thunder Drum and the Scauldron are Tidal Class dragons.
To remember these, heed this warning: "The Tidal Tides Drown Swimmers.""
2- Find the Boulder Class Rune Stone (on the path to the Lookout)
Headmaster: "Boulder Class dragons are tough earth dragons. They sometimes eat rocks. The Whipering Death and the Gronckle are Boulder Class dragons.
Just remember, "Boulders Weight Down Gobber.""
3- Find the Fear Class Rune Stone (near the School building walls)
Headmaster: "Tracker Class dragons can find anything, even if they are miles away from their target. The Deadly Nadder and the Rumblehorn are Tracker Class dragons."
4- Find the Mystery Class Rune Stone (at the Lookout)
5- Find the Sharp Class Rune Stone at the Training Grounds (near the Flight Club)
Headmaster: "Sharp Class dragons are vain and prideful. They also have sharp body parts, like spines. The Deadly Nadder and the Timberjack are Sharp Class dragons.
Remember this by saying "Sharp Dragons Need Thorns.""
6- Find the Stoker Class Rune Stone at the Training Grounds (at the end of the beach)
7- Find the Strike Class Rune Stone at the Training Grounds (behind the TRR)
Headmaster: "Strike Class dragons are really fast, amart and have powerful jaws. The Skrill and the Night Fury are Strike Class dragons.
Remember it with this phrase. "Strike Should Nimbly Fly.""
This question still mention the "Fear" class dragon, that was changed to Tracker at an unknown update.
This is the old dialogue for step 3:
Headmaster: "Fear Class dragons are sneaky and often have multiple heads. The Hideous Zippleback and the Snaptrapper are Fear Class dragons.