The Northwestern University Library has older, not recent, publications of the Chicago Public Schools. For more complete information, please visit/contact the Chicago Public Library's central library (Harold Washington Library), Municipal Reference Collection - the official depository for the Chicago governments documents. Also, for pre-1923 reports by the Chicago Government, try searching in Google Books. Most pre-1923 items are available for download as PDF.

Here are selected Chicago Board of Education (Chicago Public Schools) related items:

Annual Report, Chicago Board of Education
1859 - 1960s.
Call number: 379.773 C532a

Annual Budget, Chicago Board of Education
1960s - 1970s.
Call number: 379.773 C532a

Annual School Budget of the Board of Education, City of Chicago
1970s
Call number: 379.773 C532a

School Budget of the Board of Education, City of Chicago
1970s - 1980s.
Call number: 379.773 C532a

Annual Financial Report, Chicago Board of Education
1970s - 1980.
Call number: 379.773 C532af

Official report of the proceedings of the Board of Education of the city of Chicago
1968 - 1993. Most complete reports by the Board of Education. Here is an example (1906) from Google Books. (Go to Chicago Public Libraries for a more complete set)
Call number: 379.773 C532o 

Chicago Schools Journal
1918 - 1965.
Call number: L 379.77 C532

Also, make sure to check this list of Chicago Board of Education digital documents, including annual reports of various years, available via Internet Archive.