First Aid

First Aid is an awesome skill for every class. Tailoring is the only tradeskill that uses a large amount of cloth and if you aren't doing that trade skill, I highly recommend you pick up First Aid at lvl 5 when it becomes available. First Aid lets you make 2 things - Bandages which act as quick and powerful heal over time and Anti Venom which removes poison effects.

Here is a listing of the bandages that you can make: Bandage List These can be used to both lessen downtime while leveling or as life savers since their timer is independent of the potion timer. You should be able to ask a guard in any of the main cities to find the First Aid trainer. Turn that dropped cloth into something good!

Details on the book to learn Expert here

Artisan First Aid and Artisan level bandages are learned from:
Doctor Gregory Victor in Hammerfall, Arathi Highlands for Horde
Doctor Gustaf VanHowzen in Theramore Isle, Dustwallow Marsh for Alliance

For the Horde, the quest to learn Artisan First Aid begins with the First Aid trainer in Orgrimmar. The quest becomes available once 225 skill in First Aid is reached. The next step of the quest is given by Gregory Victor in Hammerfall, who asks you to use an item (which he gives you) to heal 15 injured NPCs in the building in speedy fashion. After doing so, talking to him again will complete the quest and Artisan First Aid is the reward.

Once you reach the appropriate level of First Aid, the Heavy Mageweave Bandage, Runecloth, and Heavy Runecloth recipes are also learned from Gregory Victor/Gustaf VanHowzen. There is no cost associated, just talk to him and he'll offer to teach the recipe.