These books by L.J. Smith are insanely good.  Each volume has 3 different stories, centering around the "Night World" which is a world inside the world of humans that humans are supposed to have no knowledge about.  The Night World has vampires, witches, werewolves, and shapeshifters. 

They are very quick reads, at least for me, and always hold my attention very well.  I'm very much into books involving the supernatural, and will be reviewing more of them on here very soon :]