GraceAdler, I believe I addressed accomodation in a PM to you.
On campus, you'd probably be assigned Goldsmith Hall, the GMB, or the Pearse St. rooms. You can put down a preference, but honestly, they won't really give a crap about it and will just assign you by lottery. The nicest are in the GMB - relatively spacious rooms in suites, where I think 5-8 people share a kitchen. These rooms have their own tiny bathrooms ensuite, with showers that you can barely fit in
. But at least they're your own.
Pearse St. and Goldsmith have smaller rooms. You'll probably have a few lectures in Goldsmith hall, which is underneath the residences. These are rooms in a suite where there's a sink in your room, but each suite shares 2 bathrooms/showers, and a kitchen/living room. There's not a lot of space. For this reason, I would suggest PACKING LIGHT for your first year - I know had I accepted rooms, I would not have been able to cram all my stuff into a goldsmith room.
They ARE expanding Trinity Hall this year, so it's very likely that as a 1st year, you'll be assigned there. Trinity Hall is in Rathmines about a 40 minute WALK to Trinity, 10 min. bus depending on traffic. This could be a major pain in the ass, especially if you plan on participating in sports. However, I know a few Trinity Hall residents who love it there.
Rooms on campus aren't all that expensive, although you have to deal with having to move out after exams, vacating at Christmas, guards checking your status after midnight, and having to sign in guests before 8 pm which is a drag after a wild night.
You could also look at areas around Trinity. You will pay a bit, but it might be worth it. For instance, I think of my place (600 eu / month) like this - if I was going to med school in Boston, I'd be paying this or more for a crappier place than mine. My apt. (I share with another person) is very nice and rather spacious.