The National Archives of Ireland now has the census records for 1901 and 1911 for all counties online. These databases are free and searchable by all categories. What a valuable resource to those of us researching Irish records! Many of my ancestors had come to the United States by this point in history, although they had siblings and parents that stayed in Ireland. I like learning about as many extended relatives and friends as possible, you may find many hidden clues and resources this way and every piece of the puzzle helps.
The website also has a variety of articles on the early 20th Century in Ireland in different counties. Here is an article about County Cork. Several photographs also give an enlightening glimpse into life at that time.