Azsuna: 57.9, 15.1: In the north-east corner of the zone, in the Ley-ruins of Zarkhenar.
Highmountain: 31.4, 63.8 Located in the south-west portion of the zone, right on the border to Val'sharah. It's actually a great way to access the eastern part of Val'sharah via glider. Fairly close to a flight path and southern PvP tower.
Val'sharah: 51.2, 56.1: The roof of the Temple of Elune. Should be pretty easy to use a glider and hit any point on the western half of the map from here including Black Rook Hold.
Stormheim: 31.3, 60.5: In the mountains of the western edge of the zone. Sufficient elevation that you can glider to nearly anywhere, I'd say.
Suramar: 33.4, 50.4: In a building right next to the flightmaster in Meredil.