I felt I should highlight the genealogical research tools which I find very useful:
The 1911 Census which is online FREE for all 32 counties of Ireland and is at: 1911 Census
Note, the 1911 Census lists how long a woman has been married (unless she is a widow) and how many children she had and just how many of them were still living in 1911. This kind of information can be useful when using civil records to identify when marriages took place etc.
The 1901 Census is not online but is available on microfilm. The Cork County Library has the 1901 Census for County Cork, on microfilm and when you have identified where your family was at in the 1911 Census, it may be possible to find them in the 1901 Census as well. However, the 1901 Census should be online FREE in a few months.
The Civil Records Index is also online at:
Civil Records Index
You can search and then order photocopies of certificates for €4 from the General Register Office in Roscommon (General Register Office, Government Offices, Convent Road, Roscommon). This index goes up to 1958.
Griffith’s Valuation, a survey of all Ireland done in the mid 1800s is FREE at:
Church records for the Diocese of Cloyne are online at:
Diocese of Cloyne
Note some of North Cork is in the Diocese of Kerry and these church reocrds are now online (not complete) at: Diocese of Kerry
The other resource which comes to mind for Cork City is the North Cathedral (North Parish) Catholic records. A hard copy index (up to 1900) for these is available in the Cork County Library. The index lists baptisms by family group which is useful. These records go back to the 1700s. Note the library is closed till the 29th October 2009 as it is moving premises.