Ace,welcome to the Forum.
I believe Texas high schools use NCAA rules.If not,someone will correct me.You can find them online at:
http://www.ncaa.org/library/rules.html
You'll need PDF to see them.Just click on the basketball rules,or probably better for you,the illustrated basketball rules.
As for the parent problem,always have the gym administrator,or-if you can't find one-have the head coach of the home team deal with them.Just stop the game until they're calmed down or ejected.Forget about the technical foul for the parents' actions.Don't penalise the ball players for someone else's action.
Good luck with your officiating career!