Check out the Cook County, Illinois GenWeb site. Lots of great ideas for sources of information there. The Newberry Library in Chicago is an excellent source of information relating to Chicago genealogy. See: http://www.newberry.org/nl/genealogy/genealogyhome.html The Chicago Public Library is also an excellent source for research. For Genealogy Information at CPL, see: http://www.chipublib.org/008subject/010ssh/genealogy.html There is a Rootsweb list serve that covers Cook County, Illinois; the people on this list are helpful and knowledgeable. The Chicago city directories not only list Chicago residents (usually just heads of household, working individuals, and widows) but they also tell where people worked and/or what they did for a living. The first directory was published in 1839. It was followed by one in 1844 and then they continued through to 1928/29, with a few gaps, most notably between 1917 and 1923 and 1923 and 1928/29. Directories are available at most of the large research centers in the Chicago area and they are also available through the Family History Library system; the earlier directories are on microfiche and the later ones are on film. A few directories are available online: 1844 1855/56 1928/29 Reverse Directory (This directory is unique in that it provides spouse names; a name-order directory is also available for the same years) Another approach would be to check out census records. They are available at the Federal Archives and Records Center (76th and Pulaski) or they are also available online, for example, at Ancestry.com (subscription site). The Wilmette Family History Center has a large collection of Chicago and Cook County vital records films including a full set of Chicago birth registers 1871-1915, Cook County marriage licenses, 1871-1916, Chicago death certificates 1878-1947, Archdiocese of Chicago parish records to 1915, and Chicago city directories from 1839-1928 (with the same gaps listed with the Newberry holdings below). The Arlington Heights Memorial Library also has an extensive collection of Chicago directories and the Chicago Tribune, both on microfilm. If your family came to Chicago before 1872, there are a minimum number of records available. The Chicago fire destroyed many government records including early marriage licenses and other vital records. I strongly suggest starting with the Chicago directories. The Newberry Library has city directories for 1839, 1844, 1846,1853-1857, 1859-1917, 1923, 1928, as do many of the other large research centers. They offer a "Quick Search Service" and will do lookups for you for a fee. There are also a number of individuals who offer lookups as well; compare prices before ordering. Be aware that Chicago changed its house numbering system in 1909, and some street names changed too. Second, once you find your family in a directory, check the census. It will help you eliminate families that aren't yours. After you're sure you've found who you're looking for, and you've figured out where they live, try to find the church they went to and try to get copies of those records. Newberry has copies of a few of the surviving records. It's one of the best sources of information for pre-1916 Chicago. The Wilmette Family History Center has all of the Archdiocese of Chicago parish records for Chicago up through 1915 on microfilm.