It has been 15 years since I was there.......the Temple Bar area was / is a huge night life area. We walked everywhere......but also did the hop on hop off bus for one day just to get around quicker, it also went as far as Phoenix Park which is quite a hike. The stretch from Trinity to Guiness is very nice. Check out Christ Church Cathedral, St. Patrick's Cathedral, and Dublin Castle, The area on the north side of Ha' penny bridge is a nice shopping district. The Jameson Distillery is on that side of the river and has tours as well if IIRC. Guiness is not a factory tour, it is only a museum.