Michigan Department of Education. Great site for information
on districts around the state - can be a little difficult to locate what
you're looking for.
Current State School Aid Update. Short (2-3 paged) PDF
bulletins published every month summarizing state action regarding school
funding.
Foundation Grants. PDF document listing the foundation
grants (base per pupil funding) for all districts in the state starting
with their pre-Proposal A base and continuing through fiscal year 2007.
Current Funding Crisis. Good article from the Detroit Free Press
discussing the current (May '07) crisis in K12 funding. (User
suggested!)
Maps. Maps of ISDs and individual school districts.
Also includes maps of House and Senate districts with their school
districts.
Supplemental Funding. Excel spreadsheet detailing additional
funding (above the current base of $7085) received by districts throughout
the state.
Bulletin 1014. "...contains various pieces of financial
information about Michigan Public Schools including revenue and
expenditure per pupil. They also include the fall pupil count, average
teacher salary, and taxable value information." (Dept. of Ed.)