Went through the few threads of this and have the following. This is subject to change when they lower the levels of the mobs we need to fight to learn the skills (aka not fighting lvl 25s to learn a lvl 16 skill etc) Feel free to chime in and add/update the list
Read in the wind 1 - lvl 26
Spiders outside Trengal keep
Infineum Simularum , southern infineum mine fields
Read in the wind 2 - lvl 36
Roaches in Darguns tomb
humanoid´s in the cave of Karrus Hakrel
River palace

Read in the wind 3 - lvl 46
Handlers in Raz (easiest option imho, they use the skill at roughly 50% hp)
Flame AND Flare maidens in raz