Chicago is located in Cook County. For questions or photocopies, try calling the Cook County Law Library (312-443-5423) and/or one of the law school libraries listed under "Illinois."
Chicago is part of the Cook County Court System, which has six criminal divisions (Chicago is the 1st division) and, for civil cases, a Law Division (for cases over $30,000) and other divisions for divorce, paternity and municipal (i.e., "small claims"), chancery and probate. Circuit Court case information is available through the Electronic Full Case Docket Search, and more information is available from the Clerk of the Circuit Court web site.
Legal Data Resources (1-800-735-9207) does document retrieval from Chicago courts, government agencies, etc.
Chicago Commission on Human Relations Decisions are available on Westlaw (CHICIV-ADMIN), back to 1992.
The leading Chicago legal newspapers are Chicago Daily Law Bulletin and the Chicago Lawyer.