Marked the spots I could think of that you should go see in a red dot.
Fibbers up at the top is a good pub with a good friendly atmosphere. Plays generally rock/goth music though I've heard that it's turned a bit more scumbaggy since I was last there so maybe it's not good anymore
There's not a massive amount to do during the day apart from what's already been mentioned. I'd definitely look around the sites I pointed out. Dublin castle is well preserved if you're into that sort of thing. Trinity is pretty impressive to walk around (unless you're used to oxford

) and stephen's green is lovely in the sunshine. Good for bringing lunch out onto.
Give templebar a try but it does just fill up with hen partys at night. I marked where I think Pans is on the map. Could be anywhere along that bit of road though so keep an eye out for it.
Dublin is pretty famed for it's theatres and performances so if you're interested then take a look at what's on in the Point and other places.
Marked the main two shopping districts though the shops are pretty common. You'd find most of them on any english high street.
I strongly recommend you to come down to galway for a few nights. It has the best nightlife in all of Ireland and is just great craic. Lovely street side restaurants and some good shopping areas. Some nice walks along the river side and even has kayak training if you're into that
Cork is supposedly nice too but I've never been there.
Anyway, map of dublin:
EDIT: Woops sorry, the northern dart station I pointed to is actually the bus station. The actual dart station is further along the green line where those black rail lines split off from it. That's Connolly station where most North-South rail lines are.
EDIT2: Forgot one of the most important places! The zoo is fantastic. Definitely don't miss it! I make a point of visiting every zoo I can whereever I go and the only one that's been better so far is Amsterdam zoo. Oh and that semi-safari type zoo in La Palmere in France.
EDIT3: The zoo is over in the NW corner of the map. Also our president lives beside it
