I began my search over nearly 14 years ago, I completed two evening classes on the subject in the early years which pointed me to the 1901 and 1911 online census where my search began.
I have subscribed to find my past which you can do from month to month. Ancestry.co.uk I found to be the best of the subscription sites, I have a yearly sub which last year cost me about 180 euro. I also took a DNA test through Ancestry which was about 100 euro and that answered many questions and help confirm what Information I had found and was well worth the expense.
List of sites to begin your search
Census of Ireland 1901/1911 and Census fragments and substitutes, 1821-51
The household returns and ancillary records for the censuses of Ireland of 1901 and 1911, which are in the custody of the National Archives of Ireland, represent an extremely valuable part of the Irish national heritage.
This website dedicated to helping you search for family history records for past generations. The website is now home to the historic records of Births, Marriages and Deaths of the General Register Office.
Catholic Parish Registers
FamilySearch is a nonprofit family history organization dedicated to connecting families across generations.
This resource goes back to 2006 and you would be amazed what information you can find.
www.databases.dublincity.ie 1908 – 1915 Electoral Rolls
These rolls can be very helpful, although the website needs so much work!! You can also look at the electoral rolls 1939 – 1962 in Pearse Street Library reading room.
A brilliant resource by Clare Santry check out her Twitter posts and sign up for notifications, well worth it