Illinois Compiled Statutes - FindLaw's hosted version of the Illinois Compiled Statutes.
Illinois Constitution - The Constitution of the State of Illinois.
Illinois Administrative Code - The Administrative Code of Illinois from the Joint Committee on Administrative Rules.
Attorney General Opinions - AG Opinions issued when requested by the legislature, any public officer of the State, or a county attorney, on a question of law relating to their office.
Legislature: Bill Information - Legislation from the Illinois General Assembly.
State Legislature - Official website of the Illinois General Assembly.
Library of Congress - Bill summary and status from the Library of Congress.