Is there a gargoyle skull or some ironwood anywhere in Neverwinter? I believe I have searched every square inch but apparently not, becuase these two items continue to elude me.

try searching this forum..

I know where you can get a gargoyle skull, go to Begger's Nest and enter the mysterious house (a.k.a. that snake cult place). You will find it in a desk in a small room.

How do you acquire the "sign of the serpent" for entry?

You will get it in a barricated house south of that building. Talk to the man inside about his brother and you'll get it.

You can get the Ironwood from the Elven druid near the great tree in the City Core. (Nyatar was his name i think) When you've done his quest, try to convince him to give you a bigger reward, if you succeed, he'll give you some Ironwood.