Coming from overseas? From Dublin Airport, a comfortable ninety minute journey on the X20 coach costs EUR 10 and includes WiFi. Just make sure you get off in Athlone!
Alternatively, competitive car hire rates are possible using this service.
You can also check your family name on the map here as a starting point to see what the best locations to pass might be to explore your family history. Or if you get a lot of results there, more specific historical information can be found here.