I'm afraid I don't know much about how the group shelf works, but am willing to suggest some classic general photography books if that is what is in order. Just tell me where to click.
Okay well I figured out how to add books to the group shelf and I added a bunch of photography books. All you need to do is on the "edit" tab on your books go to "more to do" and there it gives you the option of adding to your group shelf. Just for future reference for anyone else that wants to add books.
My book "Roda Racing: Drivers of the 60's and 70's" is a book of photography with information about these amazing drivers included. I was able to combine my two passions in life. This combination of loves is where my book comes from. I will add it to the group shelf also.