To be honest, with common surname such as Murphy and Brophy (going by a few of your posts) and no exact locations you really haven't enough details for any researcher to start searching in archives for church records, etc.
Here are a few suggestions to help you sort out what details you already have, what you might be able to find out yourself (or with a bit of help here) and where to go from here.
1) Remember to keep notes for the source of ANY information found
2) ask all possible family members for help/information (this includes 3rd cousins once removed, etc. since you don't know who might have helpful details, family photos, etc.)
3) have a look at this topic -
My Ancestor came from Ireland - where do I start?4) and look at this topic-
Introduction to Irish Records5) have a look at the Resources section of the relevant board (such as Dublin, for example) and at the IRELAND RESOURCES board also.
6) ask for help if you get stuck or have questions- but try to keep all queries for one person on 1 topic
Added- it helps to know what you are looking for and what might or might not be available. For example. If you are looking for a Thomas Ryan born 1862 there's no point in looking for a birth certificate (registration only started in 1864) or family in 1871 census (1st complete census for all Ireland is 1901).