I am going to cheat a little today. I'm going to refer you to the post from my FWC blog about how we have changed our entire way of organizing our Fiction section. It was a tremendous job, but I am LOVING it! The kids are too. I covered it all at FWCreads.com so here's what we've got going on. http://www.fwcreads.blogspot.com/2012/12/genrefied.html
I will try to post my final products soon so that if anyone else is attempting to organize by genre you can have/tweak what I've done and make it work for you.