Here is a great website:
You are able to key in options for Health Care Practiioner ----> City and State or Zip Code ----> Staff RN and here is what I got for Spirngfield Ill. as an average, according to this group:
A typical Staff Nurse - RN working in Illinois -- Springfield earns a median base salary of $44,233, according to our analysis of data reported by corporate HR departments. Half of the people in this job earn between $41,190 and $47,141.
Data as of June 2002
Base pay only 1 2 3
Staff Nurse - RN 25th%ile Median 75th%ile
Illinois -- Springfield $41,190 $44,233 $47,141
Hope this helps!