Of particular interest to the bicycle tourer, in Ireland there's a government-approved and inspected chain of guesthouses with private landladies (they display a cloverleaf -- photo above), that you can stay at but in a busy season you must book ahead, telephone numbers in a book you buy at the Irish Tourist Board online or at their local offices.
These guesthouse keepers are an important source of local knowledge, which, as I've demonstrated in the Rides 2021 thread, is crucial unless you want to cover 200 miles a day (for scale, from where I live to Dublin is only about 160 miles -- Ireland is a small country). There are a gazillion smaller roads not shown on any map of the whole of ireland, but most landladies will have a local map, and some country family hotels too; and their local knowledge is invaluable to a tourer.
You can park yourself with a local family for several days in a small town in the deep countryside and discover enough interesting and pleasant rides to keep you busy and entertained.
I feel sorry for the cyclists you meet occasionally who land in Cork and ride hell for leather around the coastline to Belfast and fly out on the third day, and then claim, in such time as they can spare from discussing their aching limbs with their physio, that they've "done Ireland"; that's just a waste of time and energy.
Also, there's a series of footpaths around the country (unfortunately not all connected, which is the eventual plan) that you can ride your bike on, exceedingly scenic and pleasant.
The best idea in Ireland, for a cyclist, I think is always to consider two points on the map and then to choose the indirect route on the smaller roads, and not to try and bite off too much in any day as the most interesting and beautiful parts of the country are all pretty hilly.
For those who'd like to try touring on an electric bike, the cafes and pubs and restaurants you stop at will usually let you recharge the battery; I've never been charged for this service but when it gets more common, I expect to be charged.
Also, another oddity, if you decide to take the bus quickly to link touring sites, letting you put the bike in the luggage is within the driver's discretion, depending on how many passengers he has with luggage, but whether he charges you for the bike is also within his discretion and the price is fixed at something under ten euro (or was, the last time I asked, years ago -- I don't know precisely because I've never been charged), regardless of the distance.
Out here in the countryside, and in Cork City the bus drivers are agreeable and friendly to bicyclists -- the middle-aged guys sitting on the rail near the bike rental at the bus station are bus drivers between trips and you can go talk to them and discover exactly on which country roads they don't like seeing cyclists because there just isn't space, and which main roads have hard shoulders all the way and are therefore safe for cyclists.
One approached me in local supermarket to ask me to tell another cyclist, a commuter to the city, to stay off the old main road to Cork -- the road I live on, described in a post in Rides 2021 (
http://thorncyclesforum.co.uk/index.php?topic=14104.msg106636#msg106636) as a road I cross often but nowhere travel along for more than 200 yards -- and to take the safer new road instead.
See also the pronunciation of "scone" in Ireland at
http://thorncyclesforum.co.uk/index.php?topic=14104.msg106655#msg106655