Get TurboTax (used it the last 6 years) Fill out and file your federal tax with them, Then just fill out the state tax form and print it, do not file it thru TurboTax. (TurboTax charges $9.95 to file state tax)
Once printed go to: http://www.revenue.state.il.us/
and file it for FREE. If you are getting a refund, direct deposit takes about 5 days and a check takes about 7 days. If you have to pay, Once filed you have 30 days to send the payment in.
My aunt. She does mine and has done mine for the past couple years. She's also done some amendments for me (which we all know since I made that thread about getting the amendments finally). She's helped me get some decent change. But its something you can pretty much do with turbo tax deluxe and the like.