How to get the Instructor Experience
It is encouraging to see the mature discussions regarding how to make the progression to instructor status in this forum.
The requirements vary greatly according to the organization sanctioning the event. You need a lot of experience. I have raced motorcycles, offroad bikes and trucks, and roadrace currently. Nonracing years on Mulholland, Angeles Crest, european autobahns, Baja and tracks in the USA and Europe help with overall skills. However, to gain instructor status the best way is to first get a competition license in NASA, SCCA, BMWCCA, PCA, SCORE USAC, CART or another sanctioned race group.
Racing is the best path to knowing your own car and improving your personal techniques. You should familiarize yourself with the Carrol Smith racing books and mine the net for all info regarding any track you want to know before you get there. Run as many HPDE events as you can. Autocross, get rides with experienced competition drivers (tough with most being single seaters), and then race with others to learn how to share the track at maximum speeds. Also any competition driving schools can be helpful, but the results will vary greatly according to your previous skill, wallet, and the schools' techiques and practices. Driving Concepts' Race school is one of the best.
Now for the hard part. You have to learn how to teach. This involves being empathetic to the new driver, assessing their skills, goals, and quickly observing firsthand their weaknesses. Then you devise a strategy to get the skills required by example, coaching, actually moving the steering wheel, driving the car yourself, and most importantly, post-session downloads where the results are critiqued without the distraction of actually driving.
As Chief Instructor for SpeedTrial, and a line instructor for NASA it is my pleasure to have instructed 100s of beginners in the basics of competant driving skills on real racetracks. Not all people make the grade. However, if you listen, really integrate what is presented and slowly work on car control, braking points, proper lines, apexes, exits, linkages of corners together, passing and car maintainance and preparation, you will improve quickly. Many of my students now have their competition licenses and others are better drivers both oncourse and on the street.
The joy of seeing someone who may have started timidly click off well-controlled laps is so gratifying. You also get to drive some of the best cars in the world! When I look for people to instruct, I look for a seasoned licensed racer or someone in the race game for a while that runs up front, shares the track, has built cars or run a number of different groups and also has a cool demeanor that will transfer into a good listener and and an all round car guy/gal.
Some general advice. Don't be a cowboy, get along with those who want to help you improve, and seek the proper experienced racers to assist your progression to a balanced driver. Negative comments, "flaming" will only alienate you and turn off your access to the real instructors who will help you.
I wish you all the best. You are driving a beautifully balanced vehicle with great capability.
Have fun, go fast, and Be Safe!