Irish research was rumored to be impossible in years past; either because of their location or their destruction. However, access to surviving records is becoming easier with digitization and the willingness of libraries and archives to put their holdings online.
One of my favorite sites is the National Archives of Ireland. Below is a list of their digital resources available online:
Documents of the Month and online exhibitions featured on the National Archives of Ireland's website provide the opportunity to view a selection of their holdings online. Also try: Ireland-Australia transportation records (1791–1853).
You should refer to this website often. They plan to put more records online in the future.
Midwest Genealogy Center