Ireland is such a beautiful place to be, the little villages, the wonderful mountains, the people, the cliffs, the mountains, there's a lot of different mountains there, makes it easy to run and hide or to stand a top of one and feel as though you've conquered the world without travelling to the overrun Himalayas. But all travel costs, so don't be afraid to budget as you can see the magical landscapes without burning a new hole in your trousers,
The buses, one of the cheapest ways to get out of the airport and into Dublin, admittedly that is only if you are travelling to Dublin as the other airports are a little tougher(Still have bus services but not as regular), there's the immediate Airlink express and they have lovely coaches, the price is reasonable then the Aircoach as well and both are around 5 euro and take about half an hour when the traffic is low, better than taking a taxi.
The trains across Ireland ( https://www.irishrail.ie/ ) are reliable and similar to taking the Eurostar, big comfy chairs run mostly on time, they stretch across the majority of the country so will take you coast to coast or through the tunnels of the you guessed it Mountainous regions. The scenery from the trains will whisk you away to wonderment, where you'll wonder if you stumbled into your very own tourism commercial, keep an eye out for the sun peeking through the clouds, the ladder to heaven. They can be rather pricey the trains so purchase in advance or choose your journeys wisely, Ireland is beautiful but tough to walk around.
There is a good wholesome supply of hostels throughout the country and as long as you stay away from the closest to central spots you should be able to snap up a good deal however the bed and breakfasts are also a good shout, there are quite a few in every city and the hospitality is like staying at grandma's house, this is not the same for all of them but the review section is generally a good indicator.
Getting around with trains, riding the buses is fun but can be very limiting and they can also take a lot out of your time budget, not just your wallet so hiring a car is a bloody great idea but bare in mind that the roads can get windy(curvaceous) in places so getting a small knock about with good mileage is key - use enjoycarhire.com to find the best deal from all the different car rental companies, never book at the airport, that is just asking to have your gold swiped.
People are friendly if you approach them that way, they were all happy to help out. Go and see Ireland and stop reading blogs on the internet about it.