Go here , there is a helpful chart on pronunciation
http://www.irishgaelictranslator.com/articles/?p=10
Be aware that Irish has 3 main dialects in addition to so-called 'Standard Irish'.
In a standard dictionary you can find a key to pronunciation marks within the definition
There are many places to find a pronunciation dictionary. Websters Dictionary is one of the most commonly used dictionaries and has a pronunciation key in it.
With the accent marks: Írusán [eerusaun] in Irish.
duninn
Phonetically 'slawn' spelled slán in Irish.
mommo
Na Ceiltigh
handsome in irish dathúil Pronunciation: dhah-oo-il
bro ga doon
cota pronounced coata
Pól. The pronunciation is the same.
BLAH-heen