Answer directly from the sticky, perpetually the first post in this forum:
Quote:
A. You need to buy the First Aid manual. For Alliance, the vendor (Deneb Walker, I think) is in the ruined city of Stromgarde, in Arathi Highlands. He is in the Alliance-friendly section, right outside the prince's room. For the Horde, the vendor is Ghok'kah, in Dustwallow Marsh.
Note: These vendors also sell the books for Heavy Silk and Mageweave bandages. Buy them!!
Now, push M. Look for a zone called "Arathi Highlands." Go there, and buy the books. If you need more help, it is north of the Wetlands, and east of Hillsbrad.