Hi Robert,
The start of your 3-month visit is here, how time flies!
March and April are indeed busy months especially with St.Patrick's day and the start of the Easter Holidays. We have an
approved accommodation search page that you may wish to use to find suitable accommodation once you have decided where to visit. It may also be that finding the accommodation first may create your itinerary depending on availability.
We have mentioned before the train provider is
Irish Rail and the main coach/bus provider is
Bus Éireann in the Republic of Ireland. From the major cities, there are scores of independent bus companies that you can use to connect with your destinations, as Lazy Days and Visit-Derry have already suggested.
Transport for Ireland has an excellent journey planner that you could use to plot your journey across the island. By entering the start and destination, you will be able to see your provider options.
I have added some extra information to a new
scrapbook, detailing day trips from Dublin and Galway and some extra information on public transport in Ireland. If you traveled to Galway for instance, then day trips from there would be a great way to see the Wild Atlantic Way coastline.
There are also tour companies that offer day tours to various locations from Dublin, Cork, and Belfast so these could be chosen as a possible base. I have added their information to your scrapbook too.
Have you any preferences to places that you would love to see?