Its a rubbish website, better than the Luas one which is devoid of any reasonably current information.
There is a site map if you know where to go
http://www.irishrail.ie/home/company_information.asp
But you will find the links point to another site
Waaaaaaaaaaaay too much javascript results in werid things happening
That said if you know where to go there are some interesting pages
http://www.irishrail.ie/realtimeclontarf/