The Cork County Library and the Local Studies section of the Cork City Library in Co. Cork are the two main local resources. The Cork Archives has a lot of material and the Cork Museum can also be useful in specific instances.
Cork Church Records
The Diocese of Cloyne’s computerized records (both Catholic and Church of Ireland) are at the Mallow Heritage Centre which is part of the paying Irish Roots project and their records are online.
Cork City Catholic Church Records are being computerized by the Cork Ancestral Project but they have no online presence even though they started the digitization process over 17 years ago (as of June 2011). Uniquely, an index to the North Parish (St. Mary’s & St. Anne’s Catholic Church) Catholic records is available in printed form in the Cork Co. Library courtesy of the Cork Ancestral Project. This is very useful and the baptisms are in family groupings where possible. Contact the Cork County Library regarding this index.
The free website Irishgenealogy.ie has church records for some of the Diocese of Cork and Ross including much of Cork City. Check to see what is included.
See the Cork and Ross website for details of Catholic parishes in that diocese.
Some areas of Co. Cork still have no records available online.
Church of Ireland records for parts of Cork City and county are available from the computerized database: Cobh Genealogical Project
The Representative Church Body Library (RCBL) in Dublin holds many of the original Church of Ireland parish registers.