Mabinogi first aid skill

To get rank F, visit the healer in Tir while you are wounded and get healing.
To rank up to E, go to Emain Macha and give the healer Anthology books. You can get them from the Observatory shop in Emain. You need about 30 Anthology books total to get to her secret shop.
I gave her books each day until she said that it reminded her of the past. Then I would do a Part Time job for her and then give her more. She also likes Heart cakes and cake slices which you can get in other towns like Tir or Dunbarton I believe.
Of course you can just go to this URL and see all the info.
http://wiki.mabinogiworld.com/index.php?title=First_Aid