i am by no means an expert, but i went to university specifically so i could take celtic mythology, so it's up there on my list of things i enjoy talking about.
additionally, i love discussing the hero's/heroine's journey, especially in regards to ya fantasy. (i don't know as much about fantasy for adults as i do for young adults, so if you have any questions about writing for young adults, ask away!)
also if you have any questions about writing in general (grammar, sentence structure, phrasing, etc.), i would love to help!