I also loved the City of Ember (not the other books in the series, really, just that first one). You should definitely read it!
I've actually used multiple POV's a few times now. In a romance you almost certainly need the hero and heroine's POV. In my YA supernatural/fantasy book I have three POV's. It was hard to adjust to writing it, and making sure each character had their own unique voice. For the most part, each of the three characters had a separate "part" in the story, but each part went toward solving the main problem. Because of that, there was very little overlap in what this character saw, versus what that character saw, etc. By that I mean I didn't have all three characters in the same scene, and then just pick one of the character's POV's to tell the scene from. In most scenes the characters were not together, and in the ones where they were together, there was a specific reason I chose to tell the scene from whichever POV I chose. Does that make any sense?