Here’s how to find (a) your legislative districts, (b) your legislators, and (c) their contact information.
Here’s the “Find My Elected Officials” page at the Illinois State Board of Elections to look up your legislators. Browse down, type in your address, click “Find Address.” A dialog box will pop up showing that it found your address. Click “OK”, then “Confirm Address.” Then browse down to find your US congressperson, your Illinois state senator and state representative, your senators and statewide elected officials, with full contact information for all.
Here’s the link to the McHenry County precinct viewer, which lets you quickly find your precinct and county board district. Click on the X in the little window that pops up at the top of the screen, then type in your street address, then click on the full address that pops up. A map will display showing your residence. Zoom out if needed to see your precinct.