John A Butz

I recomend taking a training course with a certified instructor of first aid, preferably one who will be able to focus on the areas you are likely to encounter in a dojo environment. Ask the experts advice in assembling your kit. An AED is worth the cost, in my opinion, as are the sundry clotting agents and other things that have been mentioned for serious tramua. The normal things like bandaids, gauze, painkillers (reviewed regularly for expiration dates) anseptic of your choice, etc are good to have around, and they should also be inspected on a regular basis for freshness.

Most people put a first aid kit aside and promptly forget about it, which means when you do need it, it might not be up to the task, no matter how nice it was when you assembled it years or months ago (little things like bandiads and tape and such will be used pretty consistently, and so you can run out and not know it. Big ticket items ared more likely to be unused, but it is still worth taking inventory so that you don't have to assume, you know). Make a habit of reviewing the contents of your kit once every 6 months.

You want to be sure that the majority of your seniors and regular dojo attendees have some certifications. CPR and basic first aid training will not make you into a battlefield surgeon or anything, but if you have some training you are more likely to take effective action when you need to. Again, this training should be updated and repeated often, so that you retain skills and remain abreast of the most recent methods (I have been CPR certified for quite a few years, and they seem to keep changing and simplfying that process based on research as to what works. I would have been largely ignorant of these changes had my dojo not continued to work on staying current with our certifications).

Have an emergency management plan for the dojo. Practice and plan so that you are not surprised when something happens. I'm not saying you need to devote a lot of time to it, but if you, as a dojo, have worked out what to do and who is responsilbe for what when the fecal matter really hits the whirling blades, there will be less time wasted.

Edit - Additonally, learn what you have to watch out for. Things like having a communal pair of nail clippers leap out to me as the mark of the uneducated (and a spectacularly BAD idea). When dealing with bodily fluids and injury in this day and age, ignorance is potentially lethal and life-altering. Don't make assumptions.