Novel

I have an interesting idea for a novel and it came to me through a song. I'm not sure if I should go through with it though, because it requires some research and perhaps some real involvement. It's also a subject that may not appeal to some. Yet, I really like the idea of taking a typically bad character and turning that character good. Not like, "oh he's so bad, but wait, oh he's good now" more like, "wow, so not all of them are bad," but not necessarily. You know how you can take a rat, give him a name, change a quality about it, and suddenly the rat isn't evil anymore? I wanna do that, with character development, a plot, and romance(although not with a rat).