John Grenham, the Irish professional genealogist and author, has links to a large number of useful Irish family history websites. There are links to each county in Ireland leading you to sites with information on censuses, church registers, cemeteries, Griffith's Valuation, directories and more. There are also passenger lists and links to family history pages by surname.
https://www.johngrenham.com
Lots of free Irish historical publications including county directories, a Topographical Dictionary of Ireland (1837), Atlas and Cyclopedia of Ireland (1900), census statistics, maps and much more.
http://www.libraryireland.com
This website is produced by the Irish Times newspaper. Some information is free and some can be viewed on a pay-per-view basis. Free information includes a surname dictionary, surname histories, place name database taken from the '1851 General Alphabetical Index to the townlands and towns, parishes and baronies of Ireland' and passenger lists. There are also pages for each county and lots of links.
http://www.irishtimes.com/ancestor
