Someone gets hurt. Depending on what the injury was depends on how much of an assessment you have to make. As in last Sunday's injury of Boy's friend, I was able to figure out that he probably broke a bone and then sent the friend and his parents off to the hospital. That was easy. What if the hospital's were overloaded? Or not functioning? What if you had to take care of the injury by yourself? Assessment is the easy part. What you do with the injury is the hard part, especially if you are not medically trained.
Even if you are medically trained, unless you are a vet or surgeon you probably haven't ever had to do any kind of major repair on a person or animal. For me, I'm just fine at assessing, stabilizing, and shipping them off to the folks that can fix them. But we have to be prepared to be able to fix the person if at all possible. Now that doesn't mean if I decide to look for a future spouse I will follow the lead of Todd Gray in Patriots and decide that one of the most attractive features in a future partner is someone who is medically trained. Lacking that medically trained future spouse I figured I'd better at least get a few books on the subject.
I have the Red Cross first aid handbook. That and the scout manual were my first two books on first aid. I was given a 2 volume set by the AMA called Home Medical Encyclopedia. It's an easy reading set that lists most everything that you will come across. It's a reference guide with over 5,000 medical terms including symptoms, diseases, drugs, and treatments. It doesn't do a real good job explaining how to wrap a sprain or broken bone but it's a good start. I picked up a book for a dime at a library sale called Emergency-Room Care. It lists just about everything that you can see in an emergency room and gives you the immediate treatment needed. Unfortunately often that is "prepare for surgery".
Emergency War Surgery: The Survivalist's Medical Desk Reference by the DOD is on sale at Amazon for under $11. For about $35 The Doom and Bloom(tm) Survival Medicine Handbook: Keep your loved ones healthy in every disaster, from wildfires to a complete societal collapse by Dr. Bones and Nurse Amy http://www.doomandbloom.net/ looks to be a really good book and probably one that will go into my library. Rourke at http://modernsurvivalonline.com/ is having a contest and giving away a copy of their book. I'd like to be the one to win it, but it you enter and win then I'll be happy too.
The other day when I was up the hill at GI Jim's I bought a stretcher. It's old and used but in really good condition. He had it listed for $20. It's easy to assume you will just be able to drive your vehicle to where ever the patient is and bring them in for medical help. That is not always the case. Even in my yard, in a normal year you can't drive the back pasture during the winter because your vehicle will sink in the mud. What happens if someone is out back cutting branches and they cut their leg? You may do the treatment right where they are at but then how are you going to move them the 1/4 mile back to the house? You going to carry them on your back or put them on the stretcher and drag the stretcher?
Make sure that you have your medical supplies including gauze, gauze, and more gauze. Make sure you have a box of gloves. Many infections will be prevented if the person providing the aid would just wear gloves! Their hands are full of germs that can cause infection. Having your supplies and not knowing what to do with them won't help the person in need.
At least for most injuries you don't have to react instantly. You can actually pull out the manual and read what you should do. You should practice. Have one of the kids pretend that they have a broken leg. How are you going to fix that if you can't get them to the hospital? What about a puncture from a nail going through their shoe? Kids love to be wrapped up, especially if you let them wear the sling or use the crutches for a few minutes after you are done practicing.