while I've done research on sites to visit does anyone have suggestions?

Trniity College - Book of Kells
Dublin Castle
National Museum (incredible gold jewelry)
Natural History Museum
National Gallery
Leinster House - Parlaiment
GPO - 1916 rising

There is a ton of other sights - but that should hold you for a day. (I put in my order of value IMHO)

Historical Walking Tour of Dublin
http://www.historicalinsights.ie/

Kilmainham Gaol
http://www.heritageireland.ie/en/Dublin/KilmainhamGaol/

Traditional Musical Pub Crawl
http://www.discoverdublin.ie/musicalpubcrawl.html

Guinness Storehouse.

Also chowda and a shot of Jameson's at Ryan's FXB Grill.

We just came back from 8 days in Ireland, including a free day in Dublin. I suggest that you take the Dublin tourist bus for the day. It takes you to all the above sites and more - if you have good weather (which we did!), you can sit on the top and enjoy the sites all around Dublin and get on and off wherever you want. That saves you lots of time getting from one place to the other. We wanted to get to the Kilmainham Gaol but it wasn't in the area that we were concentrating on and we gave up on the idea.
I also asked for recommendations and we went to the Chester Beatty library which is one of the most amazing museums I've ever seen. It is a small, perfectly formed museum and if you take the guided tour, you will absolutely fall in love with it. It's a collection of Asian, Middle East and Medieval artifacts and illuminations and if you have even the slightest interest in this, you will enjoy it. And it's free...
Whatever you do, you'll have fun. Loved Ireland!

yes..the "step on step off" bus, not sure that's the name- it's great, their schedule booklet lists all the sights......Kells mobbed, hard to get a look, but Kilmainham Goal really worth the trip..cafe there as well..sometimes you have to wait for the tour to start..have fun

"Hop On Hop Off" or HOHO. There are two; when I was last there one had Kilmainham Gaol on their schedule and one didn't so check to make sure if you want to go there....which I highly recommend.