Thanks for your message. I hope that someone with information makes a connection with you and helps you to fill in some pieces before your visit.
www.familysearch.org has a huge database of genealogical records including some church records for Ireland.
www.rootsireland.ie have a large collection of Irish Church records, however you have to pay to use this site.
http://churchrecords.irishgenealogy.ie/churchrecords/ have begun a project to upload Irish church records to their site free of charge. However so far only some parts of Co. Cork have been uploaded.
I did a quick search for the name Maroney in the Tithe Applotment Books in Co. Cork. There were only 5 listed:
Unfortunately, these so not offer any genealogical information but can sometimes be used to tie a person to a specific place. If all else fails perhaps the parishes listed can act as a starting point.
Some other websites that may be useful are:
The National Archives of Ireland http://www.nationalarchives.ie/genealogy1/genealogy-records/introduction/
The National Library of Ireland http://www.nli.ie/en/family-history-introduction.aspx
Genealogy Links: http://www.genealogylinks.net/uk/ireland/cork/index.html
Cork Past and Present: www.corkpastandpresent.com
Failte Romhat: www.failteromhat.com
From Ireland: www.from-ireland.net
I hope some of these are helpful and that you and your family have a wonderful visit!
All the best,