Celebrating Husbands 40th bday in Ireland for 8 days
So you're going with a pre-packaged tour then... the stops are already set and you just need to find out what to see and do along the way? I highly recommend the Eyewitness Guide ... pull up the towns that you'll be staying and traveling through and you can pick-and-choose what interests you.
Because your itinerary is set, this is likely your best bet. Asking in general, you might get some people telling you that you "must" see something that isn't necessarily on your path -- and if you try to do it, you're missing other stuff. And more importantly, making it a relaxing itinerary so you and ENJOY the trip.