I don't guarantee their accuracy ... well, on second thought I will guarantee they have errors but it is a starting place ... here are a couple sites I have bookmarked in the past

http://www.cityfreq.com:81/

http://www.radioreference.com/

Illinois freqs are at http://www.radioreference.com/apps/db/?stid=17

You can also go to the FCC web site and search geographically for licenses

http://wireless2.fcc.gov/UlsApp/UlsSearch/searchLicense.jsp