"Under Illinois law, fundraisers and charitable organizations are required to register each year with the Attorney General's office. Potential donors may then access important information such as income, expenditures, programs and administration before giving to the charity." Lots of useful information here on legal requirements in Illinois as well as FAQs.
This resource details the Illinois-specific steps to forming a nonprofit and provides a summary of the time and costs of the process. It is not necessary to hire Compliance as they have provided all of the necessary steps and links on their web site to incorporate on your own.
The booklet provides detailed guidelines for filing the Articles of Organization, as well as information on filing fees, other government agencies you must contact and legal obligations you will assume after organization. Information also is provided on low-profit limited liability companies.