Here are some useful links, Irish and Celtic based (mostly). Links
Intercelt - Excellent web site. And one great man stands behind it, Shane Diffily. Irish language, Gaelic, holidays, history, tradition, Irish music, cultural events, good humor, festivals,Fleadh,Comhaltas,many useful things & information at one place.
VirtualIreland - High quality! Site primary developed for Irish-Americans, full of up-to-date news and many very interesting things; Many sorts of chat sessions, greeting cards, good articles & great stories... If you want to spend some quality time, don't hesitate click on it.
The Dubliners - Mr. Willy Verheulpen's site, totally dedicated to the Dubliners, the great sons of Ireland. The Irish traditional music band. Playing for last 3 decades. Site is very useful and done with taste. You'll find out everything you wanted to know and see about The Dubliners.
Celtic FC - Hail,Hail the Celts are here! Want to know more about Celtic's leadership in the Premiership, just click. Or to see pictures of recent matches, to make it simple: Celtic FC on the web.
Irelandclick - If you want some fresh information about Northern Ireland situation, or Celtic FC playing, or maybe all round news about Irish happenings, this is the place! Fresh news about Northern Ireland politics. This site also has many different and interesting things. It will not disappoint.
Guinness - I would be crazy if I would start with explaining this!?! Part of Irish everyday.
Scotland.com - The name says it all. Most of the things related to Scotland can be found there.
Ireland.com - Useful site. Ireland economy,sport,news...Everything in Ireland on the Web!
Mudcat - If you need lyrics, this is the place! Thousands of Irish traditional songs lyrics. Go there and do some searching.
Welshwelcome - Welsh site.Try it out! Culture and holidays, language and other...
Irelandseye - Irish web site. Very interesting. Things like "The Leprechaun Watch" are their invention. They are famous for their live cameras projects. The history, proverbs, calendars, some of the things that it poses.
Orthodox Celts - Serbian band. The kings of Irish traditional music around these parts. Famous for their live shows. They are always much better live, than on records. And many people like them here.
Dubliners discography - Mr. Douglas Clark' web site, which includes the vast Dubliners' discography. Mr, Clark has made an excellent list of The Dubliners work through out the years, from their beginning to the recent years.
Links, many sorts of them.