This is an incomplete bibliography. Books are listed in no particular order, except that at the end of the list, I have included two books on Warren County history and biography. (Henderson County was formed from Warren County in 1841; I thought they might be helpful.)If you know of other books available, please email me with the titles and publishing information. I have included authors and publishing information IF I could find that information, and sometimes I couldn't. If you know the answers to any missing information, I would be grateful if you would let me know so that I could make corrections. Thanks!
Lomax - A Pictorial History 1912-1930 privately printed by Glen J. Smith and Bill Lionberger, 1999
History of Mercer County, together with biographical matter, statistics, etc.: gathered from matter furnished by the Mercer County Historical Society, interviews with old settlers, county, township and other records, and extracts from files of papers, pamphlets, and such other sources as have been available, containing also a short history of Henderson County.
Chicago : H. H. Hill, 1882.
Historical encyclopedia of Illinois edited by Newton Bateman, Paul Selby; and History of Henderson County edited by James W. Gordon.
Chicago : Munsell Pub. Co., 1911
History of Mercer and Henderson counties : together with biographical matter, statistics, etc. gathered from matter furnished by the Mercer and Henderson County historical societies, interviews with old settlers, county, township and other records, and extracts from files of papers, pamphlets, and such other sources as have been available.
Chicago : H.H. Hill and Co., 1882.
Portrait and biographical record of Hancock, McDonough and Henderson counties, Illinois.
Chicago : Lake City, 1894.
Henderson County, Illinois cemeteries by Virginia Ross and Jane Evans
Gladstone, Ill. : Ross & Evans, 1979-1981
Smith Creek United Presbyterian Church, Henderson County, Illinois, 17 June 1865-1900
Warren County, Illinois Genealogical Society
Prairie farmer's reliable directory of farmers and breeders, Warren & Henderson counties, Illinois
Chicago : Prairie Farmer Publishing Company, c1918.
Henderson County (Illinois) land atlas and plat book, 1982-1983
Rockford, Ill. : Rockford Map Pub., c1982
Standard atlas of Henderson County, Illinois : including a plat book of the villages, cities and townships of the county, map of the state, United States and world, patrons directory, reference business directory
Chicago : G.A. Ogle, 1900
Abstracts of marriage, death, and estate notices from the Oquawka Spectator, Henderson County, Illinois, 1848-1852
by Ruth A. Hutchinson
Abstracts of the Oquawka Spectator by Virginia Ross
Utica, Ken. : McDowell Publications, c1985
Obits extracted from Talley scrapbook by Elwilda Osborn, Sylvia Parsons, Ethel Trego
[Monmouth, Ill.] : Warren County, Ill. Geneal. Society, 1992
Obits extracted from the scrapbook of Margaret Campbell : ca.1908, 1912(1), 1915-1916, 1922-1948, 1957-1959 by Margaret Campbell
[Monmouth, Ill.] : Warren County, Ill. Geneal. Society, 
Henderson County, Illinois, 1841-1900, marriages by Virginia Ross
Gladstone, Ill. : Ross Research, c1984
History of the Stronghurst United Presbyterian Church, 1889-1989 by Stronghurst United Presbyterian Church (Stronghurst, Illinois)
Carthage, Ill. : Journal Print. Co., c1989
Portrait and biographical album of Warren County, Illinois, containing full page portraits and biographical sketches ... : also containing a history of the county from its earliest settlement up to the present time.
Chicago : Chapman Bros., 1886.
Rivers, railways, and roads: a history of Henderson County, Illinois by Robert P. Sutton, published Raritan, IL: Henderson County Historical Society, c. 1988.
The past and present of Warren County, Illinois : containing a history of the county, its cities, towns, etc., a biographical directory of its citizens, war record of its volunteers in the late rebellion, portraits of early settlers and prominent men, general and local statistics, map of Warren County, history of Illinois, Constitution of the United States.
Chicago : H.F. Kett, 1877