Get a lawyer. Doing this stuff by yourself is a recipe for disaster, particularly if you have kids or a lot of common property (like a house, or more than one car).
Even if you don't retain the lawyer for the proceedings, they will be a huge help for getting the paperwork done. And, BTW, you're asking for legal advice right now
, something which is against our Terms of Service (located at the footer of every single page on this site).
Uncontested divorces often go to mediation, and I looked it up - Illinois does have mediation. This doesn't mean kids or common property are going to be settled upon without a fight or at least wheeling and dealing.
If you don't have kids, then it's less of an issue. But for anyone with children, my God, please don't go through custody arranging without an advocate. Now is not the time to wing it.
Disclaimer: I am a lawyer but I am not your lawyer. And, as I said above, please consult one.