cial Irish governments National Archives Bishop Street Dublin. It is worth looking up and fully exploring this excellent site for many other records but the starting point is the 1901 and 1911 Census returns. This includes the 32 counties and serious researchers should study their contents paying attention to christian names, ages and occupations as these will later help identify ancestors as you progress backwards in your family tree. You are undertaking a pedigree or lineage by doing it this way, and not being sidetracked with uncles aunts grand uncles and so on. You can do this later but first go back as far as you can for direct lineage. When you have all this done and dusted, you may opt for a descendancy which is working from the furthest back ancestor and then moving forward filling in all information on family relatives up to the present day. That is a huge undertaking and not for the faint hearted. Keep careful notes of what you research.
The second step is to research the Griffith Valuations 1850? for where people lived , land valuations and maps etc. (You can also look up Street business indexes like Guys or Slaters circa 1890 etc) . Much of the Civil Register which started for Roman Catholics in 1864 is now also available on line through 'Latter Day Saints'
The Irish Genealogy Church records is also a great site for RC's and COI's if their ancestry came from Dublin Cork Kerry or Carlow. These lucky people can look up their ancestors from 1900 back to 1700. Once you get into the hang of these sites they are very user friendly and have a massive amount of information, provided you use the information like Christian names and ages already obtained from the Census records. So note everything and try to recall ages to make calculations from these older records.
For Catholics there was a pattern of Christian name selection. Generally the first son was named after the paternal father, next son after the maternal father and hird son after the father. This was a general rule and could change if for instance both grandfathers had the same christian name. The same pattern followed for the female line with the first daughter called after the Paternal mother etc etc.
Hope you find this helpful.