Renner's book may be the Bible of pinhole photography if there is one. Beyond that, I don't know that there's a whole lot out there. Many of them are tailored to children and hobbyists who want to make their own pinhole cameras -- some which include templates that you can use. I did see one such book in the past year. The camera designs were kind of juvenile, but it did include some good photographs.
You might do better to find some good blogs and online resources. f295.org, for example, is an excellent resource.