In Illinois, mediation is required for all paternity/divorce litigation. Each county has their own process, but generally what happens is that both parties (Usually without attorney's, but sometimes they can be present) sit with a certified mediator and hash out their problems. It isn't binding, and you can walk from it at any time. If a solution is reached, the mediator puts together a memorandum of understand, which can then be incorporated into a final order. Mediation is (usually) the fastest, and least expensive way to solve marital/custody problems.
Best of luck.