The books and sites I use all the time and love are:
A New Genealogical Atlas of Ireland by Brian Mitchell and Index to the Townlands, Parishes and Baronies of Ireland 1851. Use them heaps and they are beside my PC, within easy reach.
The only blog I read is Claire Santry’s, Irish Genealogy News. I always get good stuff from Claire.
For Australian research Trove is amazing. They are continually adding newspapers and it is all free.
Almost forgot Fin Dwyer’s fantastic podcasts. I listen to these in the car or if I’m cleaning the house! irishhistorypodcast.ie. So enjoyable. He is now doing guided tours of medieval Dublin and other places like Glendalough and Kilkenny. If I get back to Ireland I will definitely go on these tours.
Other occasional genealogical gems:
For Cork researchers just discovered corkarchives.ie .
irishgenealogy.ie is free and I hope they keep adding records. Covers Dublin, parts of Kerry, some Cork and Carlow.
For those with ancestors buried in Dublin’s Glasnevin Cemetery . All the graves are being transcribed and photographed. They have text as well as photo files.
I do use other sites, like Rootsireland, but can’t say I love them . Rootsireland is now a subscription site. You have to pay for a specified period of time. I like this system as I could look at up to 1,000 records in one month. Cost about $30 AUD. This won’t suit someone who wants one or two records.
On July 8, 2015 The National Library of Ireland published online all the Irish parish registers. These records have only been available in the National Library of Dublin or in the respective parishes. They are the original records which are on microfilm.
A lot does depend on the priest’s handwriting and diligence and the condition of the documents. There is no index, which means you won’t be able to just search for a person. It is a huge advantage if you know the parish and of course the county or else trawl through them all!
The records are actually in much better condition than I thought they would be. The site has been made as user friendly as possible. It is called Catholic Registers at NLI. Unfortunately there are years missing and there is not a lot of genealogical information on them. I suggest that a subscription with Rootsireland for a month in which you can look up 1,000 records could really help navigating your way through these microfilm records. There are also still records that only Rootireland has. Not sure why this is. It is an impressive site.