I want to create 2 photobooks and have a percentage of the proceeds go to charity. What are the legal issues surrounding this?

I want to cerate 2 photo books and have a percentage of the proceeds go to charity. What can I say and not say about this. The books are about animal rescue, and I was going to have several pages in the books devoted to different rescues. Buyers of the book would be able to choose which rescue they would like the donated portion to be given to. I wanted to say x% of the proceeds from the books would be given to animal rescue. Can I say that or is it considered commercial coventuring (CCV)? What about the inclusion of the rescues in the book itself. Is that CCV, too? Is there a way to get around this? If not, how do I make the CCV legal. Do I have to register as a professional fundraiser?