The National Center of Education Statistics has posted an interesting report, Employees in Postsecondary Institutions, Fall 2004, and Salaries of Full-Time Instructional Faculty, 2004-05 (NCES 2006–187).  Here is the abstract:

This report presents information from the Winter 2004-05 Integrated Postsecondary Education Data System (IPEDS) web-based data collection. Tabulations represent data requested from all postsecondary institutions participating in Title IV federal student financial aid programs. The tables in this publication include data on the number of staff employed in Title IV postsecondary institutions in fall 2004 by primary occupational activity, length of contract/teaching period, employment status, salary class interval, faculty and tenure status, academic rank, race/ethnicity, and gender. Also included are tables on the number of full-time instructional faculty employed in Title IV postsecondary institutions in 2004-05 by length of contract/teaching period, academic rank, gender, and average salaries.

Here is one of the more interesting charts:

Average Nine-Month Salaries at Four-Year Colleges
	Full Prof.	Assoc. Prof.	Ass’t Prof.
Public
Men	91,102	66,598	56,523
Women	81,719	62,187	52,265
Private
Men	95,815	66,172	55,671
Women	84,275	61,747	51,848

The authors are Laura G. Knapp, Janice E. Kelly-Reid, Roy W. Whitmore, Burton Levine & Seungho Huh (all of RTI International) and Susan G. Broyles (National Center for Education Statistics).