Moore Medical has a first aid reference card called the Fast Aid Guide. It covers 27 different life threatening conditions. It is laminated and folds up nice and compact. It retails for under $5.00.
I build first aid kits for friends and family members. I make sure one of these cards is included, along with a small but comprehensive first aid book. That book is First Aid by R.M. Anderson.
When I build one of these kits I pack three sources of first aid information in them. One is the small manual, the second one is the Fast Aid Guide, and the third is an Adventure Medical Kits space blanket which has both first aid and wilderness survival information printed on it.
Hopefully no one will be screwed up enough to lose ALL THREE information sources.
Sorry I carried on longer than I expected to
Fielddoc