lane violation
 

I was officiating a youth game and whistled a step in by Team B, I awarded the shooter another free throw. After the game I was informed by the awaiting officials of the next game, that there wasn't a lane violation due to the fact that the ball never touched the rim. I looked throughout the rules and could not find a ruling that pertains to this.

Double violation. See 9-1 Penalty 3 and 4 (4 refers you back to 3)

Linking Things
 

See 9-1 PENALTIES 2.b.
The lane violation by the free thrower's opponent is a delayed violation withheld until the free throw ends.
4-20-3 stipulates when the free throw ends.
Seems that another free throw is merited.
9-1 PENALTIES 4c. might give the easy way out, if you think the violation by the free thrower's opponent constituted disconcertion.

Then again, I might be incorrect. Cf. further responses for confirmation one way or the other.

To Quick to the Draw
 

It already looks like Bob's reply is better than mine.

I agree. ;)

Agree - penalty 4b specifically ......which as you said refers you back to 3.

If Team B stepped into the lane before A1 released the ball, then you may say that Team B disconcerted the shooter. Thus only penalize the lane violation.
If A1 releases the ball, then Team B commits a lane violation. Double violation. AP throw-in

Maybe if it was egregious enough and clearly affected the shooter, but the OP didn't say anything about that.....

I think in most cases, B1 would have to do more than just step into the lane early to disconcert the shooter.

He also didn't know what the rule was so it's very possible he could have omitted a very important fact. Certainly nothing wrong with addressing the possibility since that would greatly change the ruling.