Dublin perches on the east coast of the Emerald Isle, fronting the Irish Sea. It's served by the M50 ring road, which branches out into major highways including the N2, N3, N4, N7 and N81. This set of motorways connects to major cities across the country, and drivers regularly set out from Dublin to explore Limerick (180 kilometres), Galway (215 kilometres) and Cork (227 kilometres).
Driving to and from the airport is liable to take a bit longer than you anticipate - especially if you're out during the morning or evening rush hours. Ideally, connecting to the airport from most hotels around the city centre takes less than 30 minutes, but it won't hurt to allot double that just to be safe. Luckily, Dublin Airport is stacked with shopping and dining facilities, so if you clear security earlier than expected, there's plenty to keep you occupied. The Dublin Airport website provides a very detailed to and from the airport guide.
More than a quarter of Ireland's population lives here in Dublin, and many of the country's key landmarks are a short drive from the city centre. Farther out, the countryside's riddled with archaeological sites and spectacular coastal scenery. It's difficult to really appreciate this if you're limited by public transportation, but a car, a detailed map and an independent spirit will lay the entire country open. Car hire at Dublin Airport makes this possible.