I really hope you enjoy your trip to Dublin. Its really all about what you want to capture. There is everything from Sandymount strand to Dublin Castle. From the North Wall to Temple Bar, the photographic opportunities are endless :)
I love Dublin Castle and the Chapel, the Quays and the views of the Liffey are great too, but that may be a bit too touristy for you. As +Eileen O'Duffy
has suggested the Baggot Street area is nice with the canal. If you take a walk along the canal to Portobello you will get some great images.
If you're interested in meeting up let me know I can show you some of the sights, but as I work weekends it may be late in the afternoon.
Thanks +Brian J. Kelly
for giving me a shout :)