Hi Kerry,
Could you please post your message on the Myross parish page here: http://www.irelandxo.com/group/myross-cork and the Castlehaven parish pahe here: http://www.irelandxo.com/group/castlehaven-cork
The Roman Catholic church records for the diocese of Castlehaven (Cork & Ross) (this covers both Castlehaven and Myross), start from 1842 to 1880 for baptismal records only. These are available from the National Library of Ireland, Pos. 4774. If you have any difficulty, you could try writing to the parish priest for more assistance.
Civil registration records are available from the General Register Office (GRO). These start from 1864 however. You can access the website here: http://www.groireland.ie/research.htm
You could also try checking the land records called the Tithe Applotment Books (1823-38) or the later Griffth's Valuation (1848-64). Griffith's is freely available here: www.askaboutireland.com or here: www.failteromhat.com Failte Romhat has lots of other useful links you could try looking at. This has lots of links to records related to County Cork.
There are also Reproductive Loan Fund records for Castlehaven. These date from 1838-48 and gives names with acocunts of deaths and emigration. This can be found at the UK National Archives, T 91 here: http://www.nationalarchives.gov.uk/
Please make sure you link anyone else in your family who is interested in their Irish heritage to our site - and indeed anyone else you know of Irish heritage.
Kind regards,
Sinead Cooney
Genealogist (Ireland XO)