The March-April issue of Academe consists of the Annual Report on the Economic Status of the Profession (commonly known as the "compensation survey.") The report, assessing trends in full-time faculty compensation over the past year, is available to all readers.
See this year's report, Losing Focus: The Annual Report on the Economic Status of the Profession, 2013-14.
See also an online-only supplement, The Employment Status of Instructional Staff Members in Higher Education, Fall 2011 (PDF)
The report's appendices and other supplementary materials are available here.