In researching your Irish ancestors these sites may be helpful:
Family Trees on Rootsweb World Connect (free)
The Irish Times Ancestry section. This includes an online version of material in found in John Grenham’s Tracing Your Irish Ancestors, Third Edition. You can get this book through Amazon. I recommend Amazon as I have found they are so much cheaper than specialist genealogy bookstores and it is often possible to get a second hand copy. I have never had any problems with Amazon.com either.
Jane Lyons has a comprehensive site called From Ireland.
The Index Page for the Ireland Genealogy Projects
Failte Romhat The genealogy site of John Hayes.
Very detailed listings and descriptions of many Irish sources available at Irish Ancestors.net by Sean Quinn at Rootsweb Freepages.
Census Finder has links to numerous good sites.
Latter Day Saints Free Record Search
The Irish Family History Foundation . Fee of 5 Euro to view a record.
Tipperary Family History Research commissioned research only.
Cemetery Headstone Transcriptions Ireland by Sue Grieves