Almost certainly, the most famous and learned discussion of the proposed Constitution was a series of 85 essays written by Alexander Hamilton, John Jay, and James Madison between October 1787 and May 1788. (More information here.) The above link leads to a respected published edition, but many sites are available online, including one provided by the U.S. Congress.
Most recent information from of this "annual report on American journalism," covering major trends, content analysis, audience, economics, ownership, online trends, and more. From the Project for Excellence in Journalism. You also can read earlier editions.