Leveling First Aid in Mists of Pandaria is a breeze. There’s nothing really new, just crafting Windwool Cloth instead of Embersilk Cloth a few dozen times. There are really only two crafts that you need to use and both require nothing but Windwool Cloth. To go from level 525 (max level in Cataclysm) to level 600 all you need is 100 Windwool Cloth, or 5 stacks. Here is out it all works:
Leveling First Aid
Learn Zen First Aid from any of the First Aid trainers.
Levels 525-550 (also available at level 500)
Craft 25 Windwool Bandage – 25 Windwool Cloth
Craf 25 Heavy Windwool Bandages – 75 Windwood Cloth
A Cheaper Way?
You can reach level 535 by crafting Heavy Embersilk. You could save a few gold by having 3-4 stacks of Embersilk Cloth ready on the day Mists of Pandaria goes live and use that instead of Windwool Cloth to reach level 535. This would give you a slight advantage over other players leveling through MoP.
Tip: Have you ever wondered how players have so many level 85s or how they can level an 85 so quickly? I use and strongy recommend Zygor's in-game leveling addon which will enable you to level in 5 days of played time. You can find a free version of it here.