I get calls from people who have cases at the Illinois Human Rights Commission ("IHRC") regarding how to proceed with discovery. My first piece of advice is to tell them to hire an experienced employment lawyer. Discovery is where a case can be won or lost. It is also instrumental in getting information that will lead to a good settlement. For example if you have a sexual orientation or sexual harassment case pending before the IHRC, you would want to get evidence the other side has of the discrimination. A good starting point would be text messages and emails that were uncovered by the company investigation.
Usually if you file an internal complaint of discrimination the company will do some sort of internal investigation. Documents uncovered during the investigation may be very relevant to your case. The documents get even more important if the company engages in retaliation against you after you complain about the sexual harassment or sexual orientation discrimination. There are no short cuts when it comes to discovery and how clever and complete your discovery requests are may decide how much money you end up with in your pocket.