Higher Learning involves reading a number of randomly spawning books around Dalaran. As a reward, you receive—in a somewhat roundabout manner—a [Kirin Tor Familiar] companion. Upon completing this achievement, you receive a book titled [The Schools of Arcane Magic - Mastery] via in-game mail from Rhonin. Using this book will teleport you to Archmage Vargoth's Retreat, at which point you may speak with him to receive your companion. The [The Schools of Arcane Magic - Mastery] book will remain usable in your inventory until deleted.