"Seriously, CoachChris, pay the fee to take your 6 & 10 year-olds to a known pitching instructor. The arm you save, may be your son's."
It's funny that you say this, since this is part of how I got started on this.
Last year the parents of 4 of my guys each paid $40 bucks per session for their sons to work with a local pitching coach. I was too cheap, so I taught my son myself.
Over the course of the season the 4 guys who went to the coach got worse (one went from giving me 2 or 3 good innings to not being able to throw strikes) while my son got better (gave up just 1 earned run and 2 hits in 3.5 innings during the the playoffs).
That's when I realized that a lot of the "experts" don't know what the he)( they're talking about and I ought to educate myself.