I was first introduced to the "hero's journey" a couple years ago at a small writer's conference. The workshop instructor used the movie Star Wars (the original one with Luke still on his home planet) and then pointed out all the different stages of the journey for the hero.
Not long after, a friend recommended the book The Writer's Journey by Christopher Vogler. Based on Joseph Campbell's mythic story structure, Vogler breaks it down so that anyone can understand and apply to their writing.
One of the things I like about the hero's journey is how it's kinda like a road map. It gives you a general direction of where to go and mileposts along the way. And while this sounds like something that only works in fantasy stories, it applies to all genres. Even a mystery has a "Call to Adventure," "Tests, Allies, Enemies," and "Return."
I'd encourage everyone to learn more about the hero's journey and it just so happens someone out there formed a group so we can do that. This group is dedicated to learning, using and teaching the mythic structure for writers called The Hero's Journey. You can find it here. It's a new group, just getting started so give it a look see.
Also, get the book The Writer's Journey by Christopher Vogler. I've got "LOTS" of writing books but this is one of my favorites.