I'd put only emergency phone numbers and the quickest 1-aid-at-a-glance summary in the binder. If you have time to read more than that then you can dig out the book or other 1.aid reference manuals.

As Art said, some things must be resolved RIGHT NOW - which leaves little time for reading, perhaps a 5-bullet point check list. You may have some additional phone numbers at hand for such things as information about poisonous creatures in your area, the local police or similar.

But many injuries or illnesses are not that immediate life threatening. Wrap it up, provide lots of comfort and consolation while at the same time ask as much about the symptoms as you possibly can. Then slip out and re-read whatever manual you have at hand before you decide on further action (treat here, transport elsewhere, need professional assistance).