Q. In running text, what is the proper way to write out a URL—with the www or without?
A. Please see CMOS 8.191 (“Titles of Websites and Web Pages”):
Many websites either do not have a formal title or do not have a title that distinguishes it as a website. These can usually be identified according to the entity responsible for the site along with a description of the site and, in some cases, a short form of the URL. For example, http://www.apple.com/ might be referred to in running text as Apple.com.