Check out the CMP Website and find some Junior programs in your area.
Get involved with the CMP Clubs and they (via the CMP & NRA) will help you with equipment, rifles, and ammo).
The same thing with High Power. The NRA has great programs for juniors, each state is eligible for what they call Whistler Programs. That's a junior team match where you go to Perry and compete against junior teams from other states. Again, you'll get a lot of support from the NRA, and different companies, (for example Sierra provides bullets for our Whistler Teams.
I'm not sure of the upper age of 4H, but might also check with your county extension agent about 4H programs in your are. 4H shooting sports is the fastest growing 4H activities out there. Again you get support, our club members furnish ammo and instructors to our 4H shooters.
There is also the CMP GSM (Garand, Springfield, and Military) vintage rifle programs. Again find info about this on the CMP website.
Shoot every NRA Light Rifle and CMP Rimfire Sporter Match you can. Besides giving you experience it will hook you up with experienced shooter who will help you along the way.
NRA 4 Position and ISU (International Shooter Union) 3 position small bore programs are good, but gets a bit expensive in the equipment areas. International Shooting is the most demanding. This takes you all the way to the Olympics.
You're best source right now is the CMP, visit their web site,
The Civilian Marksmanship Program:
CMP Board of Directors
Meet the CMP Board of Directors
Gary Anderson, Director of CMP Emeritus
Meet the Director Emeritus of CMP,
Mr. Gary Anderson
Orest Michaels, CMP Chief Operating Officer
Meet the Chief Operating Officer,
Mr. Orest Michaels
The Civilian Marksmanship Program (CMP) is a national organization dedicated to training and educating U. S. citizens in responsible uses of firearms and airguns through gun safety training, marksmanship training and competitions. The CMP is a federally chartered 501(c)(3) corporation that places its highest priority on serving youth through gun safety and marksmanship activities that encourage personal growth and build life skills. Links on this page will lead you to more detailed information about the CMP and its programs.
Statutory mission. The federal law enacted in 1996 (Title 36 U. S. Code, 0701-40733) that created the Corporation for the Promotion of Rifle Practice and Firearms Safety, Inc. (CPRPFS, the formal legal name of the CMP) mandates these key “functions for the corporation:
(1) To instruct citizens of the United States in marksmanship;
(2) To promote practice and safety in the use of firearms;
(3) To conduct competitions in the use of firearms and to award trophies, prizes, badges, and other insignia to competitors.
The law specifically states: In carrying out the Civilian Marksmanship Program, the corporation shall give priority to activities that benefit firearms safety, training, and competition for youth and that reach as many youth participants as possible.
They have a lot of assets to get you on your way.
Check out the CMP E-Store, book store section. Great material, two of the best books you can get is their "International Rifle Marksmanship" Guide and the "Service Pistol Guide" put out by the Army Marksmanship Unit. The books run $6.95 each, worth their weight in gold.
Get the back ground, and if you want to coach/instruct, learn how to instruct. Take in some of college classes designed for teachers.
There are a lot of shooters out there, just about everyone who gets out of the army or law enforcement opens up some sort of shooting school, they're popping up all over, they may or may not have lots of marksmanship experience but few have teaching experience.
Knowing how to shoot is one thing, knowing how to instruct is something totally different.
Anyway I can't stress enough, the Civilian Marksmanship is your best source for the information you're looking for.
It's been around a long time, since 1904 to be exact. (1904 - 1996 it was run by the Army, called the DCM (Division of Civilian Marksmanship) in 1996 Congress changed their Charter where now its run by Civilians, but the same program only more efficient, before the DCM had to be funded by Congress, and didn't get the funds they needed, now the CMP is funded by sales of surplus firearms and equipment.
The program was created for people like you.