I feel for you. I'm also organizing ref's for our church league here in LA.
We have two one-hour training sessions scheduled. The "ref's" can attend either one.
During these sessions we cover the very basic rules with a handout. We will also explore "common misconceptions like those outlined here
http://www.sfcyo.org/athletics/basketball_rules.html)
The last thing we will go over is positioning and court responsibility. That takes about an hour.
Lastly, just prior to the jump ball, when are all gathered around, I give the following pep talk:
"Gentlemen, we are here for fun and exercise. I've seen you warm up and I know that none of you are former NBA players. Likewise we are not former NBA refs, so let's all have fun and show good sportsmanship"
If you don't have a training session I've found that the quality is really spotty.
At this level with a crash and two players are on the floor, I call a foul. Even if I close my eyes and pick. It isn't right but it keeps the fisticuffs to a mininum.
I've seen adult leagues where the players call their own fouls and it works well in our stake. Then again, I don't play 'cause I don't enjoy rugby.
Good luck.