Here are some of my favourite Irish blessings for you.
And in case you wanted to learn more about the true meaning of St Patrick's Day, here is some more fun stuff.
Catholic.org have a detailed short biography on the Saint, which includes the tidbit below. Go here to read more.
Patrick used the shamrock to explain the Trinity, and has been associated with him and the Irish since that time.
Whether you celebrate St Patrick and his feast day or not, I hope you have the best day possible!