Hmm my story would probably have 2 openings and endings, with a change in the middle of the series- not only it's pretty long, but also gradualy gets darker and darker (starting from what is seems to be a light fantasy story).
I think Within Temptation's Forsaken would be a pretty good opening- though probably to the second half of the story.
This or Mein Herz Brennt, Rammstein ft Tatu version:
I'd definitely want this one as an ending:
... though Lullaby would also be great: