Civil birth marriage and death records, from 1864 (and from 1845 for non-Roman Catholic marriages) are held by the General Register Office of Ireland.
The Irish Archives Resource web site has lists of material available in archives across Ireland.
Published books, newspapers, directories and other sources are available in Cork City Library, local studies department, Grand Parade, Cork http://www.corkcitylibrary.ie/ and Cork County Library, Model Farm Road, Cork email@example.com.
The National Archives of Ireland, Bishop Street, Dublin, has ‘Griffith’s Valuation’ c.1847-1864, the Tithe Applotment Books 1823 – 1837 and the 1901 and 1911 Census and also provides a genealogical advice service. http://www.nationalarchives.ie
Many parish/church records for Cork are now available on the Irish Genealogy web site http://www.irishgenealogy.ie/ .
Catholic church records are also to be found with local parishes http://www.corkandross.org/ and http://www.cloynediocese.ie/ and also in the National Library of Ireland http://www.nli.ie/. For Church of Ireland (Anglican) parishes see the Representative Church Body Library, Dublin http://ireland.anglican.org/ For Presbyterian congregations in Cork contact Rev. John Faris firstname.lastname@example.org and the Presbyterian Historical Society, Church House, Belfast.