The following video is a promotional and demonstration video of a small arms instructor. The NRA and the state of South Carolina recognizes this instructor with certifying paperwork, which is more official documentation than some military and police small arms instructors may have.

Some maintain that only taking formal instruction is valid training while competition should be avoided as it is not training (ignoring how dictionaries actually define the word training) and that it leads to bad habits/ training scars. So you should only take a class from a certified instructor to avoid bad habits.