Here we go:
The # 16 Dublin Bus and follow directions, per hostel's instructions, above:
Depending on how much travel you want to do by bus, DART or Luas within Greater Dublin,
this Leap Visitor Card will work well, including the journey to and from the airport:
I just arrived home today. I bought a return Airlink ticket from 365tickets online for about £8. Download, print and show driver at 747 bus stop at Dublin - Terminal 1 or 2. He gives you a return ticket. The closest stop is probably Cathal Brugha Street. Turn right onto O’Connell Street, pass Parnell Square and it is a few blocks up. You can also buy your ticket on the bus.
Thanks guys, i got the number 16 bus,
Good stuff, have a great trip. :)