Hi pamom,
I understand being nervous in front of the parents, but just realize that you are the one up there giving your time, and they really aren't in a position to judge! Especially since there are 15 other Scout's parents out there that did not make the commitment to volunteer like you did.
My philosophy is that I will "do my best" and if they ever have a complaint, they are more than welcome to take over from me. We had 8 Tigers last year with me as Den Leader, and parents hesitant to help out - this year we have grown to 15 wolves, and it was like pulling teeth to g