I dont know alot about chicken first aid, only what I have learned from my 3 1/2 month old flock... But here is the few thing I keep on hand..
Q- tips (good for applying meds to wounds, or getting pasty butt off)
Peroxide & Squrit bottle (mix water and peroxide in bottle and it makes it easer to disinfect a wound).
I also used Iodine wipes (in Tx we call it monkey blood) this also disinfects wounds.
Neosporin (use the original, I heard the Neosporin that has the pain reliever in it can hurt/kill the bird).. I used some old expired neosporin because I heard as meds age they lose there effectiveness (so it wasnt as strong)..
Also sissors (to cut the feathers back away from the wound).
That is about all I know, but will keep this post as I would like to make up a first aid kit too..