you will always get that as a GM. no matter what there will always be players that think that your trying to screw them over or something. Don't take any offense from it.
I remember i first time i GM.... ya... lets just say that i had alot to learn, but i had good friends who offered alot of advice over the years so that each time i took the GM spot, i got better and better..
My only suggestion to new GM's is to watch what you would call the best gamemasters as they run games and how they do it. You can learn alot by seeing how they do pacing, tempo, suspense, balance, and drama.