Non-Fiction and Self-Publishing

While reading Publisher's Weekly, I came across an article analyzing the spending habits of people who purchase self-pub books. It mentioned that NF is primarily purchased by men as they prefer more academic and professional topics. Interesting but no great surprise. What I did spark my interest was trying to figure out how to know if these NF titles can be relied upon to present good information. Do these authors have their respective associations read them and provide feedback? Do they have editors to help them correct grammar and focus on the topic at hand? How do we know the authors aren't just making it all up? How do we, as librarians, figure what is reliable and what is not? I mean I attempted to read 50 Shades of Grey and could not get pass the halting, awkward writing. There is someone who desperately needed editor...