Post the sorts of non-fiction you blog about.
If it's not fiction-related, I'll most likely blog about (auto)biographical, historical and occasionally political stuff, as well as all things international, travel and languages; with the occasional cookbook or photography/coffee table book thrown in for good measure. And, err, any- and everything related to cats.
My non-fiction reads are generally history or biography, but I also read some science. And knitting books, for that matter.