I know bylaws. But I don’t know the rules in every state. I just found this great book that has—among other great things—an appendix that lists, state by state, what is required to form a nonprofit organization.
It’s possible that some stuff may be slightly out of date, but at least it tells you where to look in your state.
Check out this book by Mark Warda, titled, simply enough, How to Form a Nonprofit Corporation