It seems to me like problems come in a variety of required response speeds, but there's a natural threshold to distinguish fast and slow: whether or not you can Google it. The slow ones, like getting an eviction notice from your landlord or a cancer diagnosis from your doctor, can't be ignored but you have time to figure out best practices before you act. Fast ones, like getting bit by a rattlesnake or falling from a high place, generally require that you already know best practices in order to properly implement them.
Also useful would be the meta-guide, which just separates out which problems are fast and slow (or how fast they are). Getting bit by a tick, for example, seems like it might be quite urgent when you discover one biting you, but isn't; you have about 24 hours from when it first attaches to remove it, which is plenty of time to research proper removal technique. Getting a bruise might seem like you have time, but actually applying cold immediately does more to prevent swelling than applying cold later does to reduce it.
Of course, this is going to vary by region, profession, age, sex, habits, and so on. I'm sort of pessimistic about this existing at all, and so am interested in whatever narrow versions exist (even if it's just "here's what you need to know about treating common injuries to humans"). Basic guides also seem useful from a 'preventing illusion of transparency' perspective.
First aid seems very close to this category, consisting of immediate assistance to an injured person. The major differences are that (a) it's specific to physical injuries and (b) it involves things one person can do to help another, rather than things one should do to help oneself.
I've taken first aid training in Berkeley, California, and the guide to CPR was helpful, although the rest seemed to be mostly about meeting legal requirements and not that effective in actually teaching stuff (as evidenced by me not remembering it).