There are no end of English academies in Ireland so how do choose the best school?
Firstly, remember that Ireland is full of students learning English as a second language and many of them may be from your country. Whether you think so or not you will inevitabily be sucked into conversations in your native language. This means our first recommendation is to avoid Dublin. Dublin seems to have as many students learning English as there are native English speakers, especially in summer. This also means that Galway or Cork are the obvious second choice for your English schools in Ireland Both cities are wonderful locations but do not forget that the people of Cork have a strong accent and Galway is almmost as popular as Dublin with English language students.
Consider an intensive course with fewer English language students and therefore less likelihood of meeting someone of your nationality. Small classes also give you more opportunity to speak English in class rather than just noting down grammar explanations etc. What's more if you are shy, you will feel less inhibited about speaking English (and making mistakes) in front of a smaller group.
Finally, should you live with a family or in a student residence? This is almost an item for discussion in itself. I personally, would run a mile from the family set up simply becasue i know from experience just how bad it can go. However, there are also endless English students who have attended endless English courses in endless English school in Ireland and elsewhere that would thoroughly recommend this option. My warning is that the typical family in Ireland is not so much worried about you learning but rather that you help them pay the bills.
With regards to the English schools in Ireland i cannot recommend one more than another but do ask for many details as possible before choosing your English course, especially in summer. The reason is that in summer all the English schools are mad busy and they do not have time to worrry about little details such as student satisfaction.