Apply for an Irish passport before you make any travel arrangements. An Irish passport takes about 8 weeks to get but there is no guarantee that you will have your passport in this time. Just to be safe, apply for the passport at least three months before you travel. To get an Irish passport, you need proof of your citizenship, a completed application, two passport photos, a fee and a signature from a local Garda Síochána.
Look through some tour books on the United States and pick out what locations and things appeal most to you. You can only stay for three months; not enough time to see the entire country. You may want to travel from city to city seeing as much as possible during that time or you may want to settle into one city and try out living like a local.
Make a budget for your trip to the United States. You may find that traveling is much more expensive than you anticipated. The United States does not have as many hostels as Europe, so finding affordable accommodations could prove to be tough. The U.S. also does not always have cheap and convenient public transportation, so you may find that you need to rent a car depending upon where you're going.
Buy your plane ticket from Ireland to the United States. Be aware that how much you pay will vary greatly depending upon which airport you choose and when you fly. If you plan to visit several cities, check several different airports to find the best prices. You can also save money by flying in the middle of the week on a Tuesday, Wednesday or Thursday.
Plan your itinerary, especially if you have never been to the United States and you don't know anyone there. Some places are relatively easy to navigate for newcomers. In other areas, like New York City, you will find that making a reservation at a hotel can save you a lot of money and trouble. You should also plan your transportation. If you have an Irish driver's license, you can rent a car in the United States. If not, you'll need to depend on a mix of planes, buses and public transport to get you around.
Show up at the airport at least two hours before your flight takes off with your luggage and your passport. You don't need a visa, thanks to the United States' Visa Waiver Program.
