National Survey of Salaries and Wages in Public Schools (2005-06)

Edweek.org:

For the third year, The National Survey of Salaries and Wages in Public Schools was released to Education Week by Educational Research Service as part of a research partnership.
The survey of more than 600 school districts conducted by ERS, a nonprofit organization based in Alexandria, Va., that has been conducting the survey for more than 30 years, revealed that district size has a more pronounced effect on the salaries of superintendents than any other staff category.
The strong relationship between district size and salary for more senior administrators weakens among lower-paid education professionals. On average, assistant principals, teachers, counselors, and librarians earn the highest salaries in mid-sized districts serving between 2,500 and 25,000 students.

Full survey [292K PDF]