Douglas County, IL Genweb Project a collection of online resources for genealogy researchers
Illinois Public Domain Land Tract Sales Database - for Douglas County select this county and then enter the surname (at least first 2 letters) of the person whom you wish to search on  (a government database of over 550,000 19thC land sales in Illinois - info on obtaining original copies is here )
Genealogy Trails History and Genealogy Project - Pages for This County you will find user contributed records of births, deaths, marriages, military and newspaper extracts at this site
The Tombstone Transcription Project - cemeteries for Douglas Co. IL
US GenWeb Archives for Douglas County cemeteries, newspapers, wills, military rosters etc recorded online

Additional Resources

Illinois Public Records Search find living & deceased family members/relatives including address, phone number, age..
Illinois Birth Records
Illinois Marriage Records
Illinois Divorce Records
Illinois Death Records