Glad to hear you'll be seeing Ireland, it really is beautiful. To give you an idea of the distances, if you drive quickly, you can get from Downpatrick in the northeast to Limerick in the southwest in seven or eight hours, but you'll be pretty tired.
Belfast is only about two hours north of Dublin, and the Coast Road from Belfast to the Giant's Causeway is really worth seeing. While you're near the Causeway, you could pass by the village of Bushmill's and visit the world's oldest distillery, and sample some Bushmill's where it's actually made. Crossing into the North is like driving from one state to another in the US, there aren't any Customs posts (at least there were none when I was there in October 2000). The roads are many parts of Ireland are narrow, so don't be surprised when you wander onto the grass occasionally. You'll find that Irish drivers are pretty daring, but also friendly and courteous. If you like shooting landscapes, you'll love the lighting. Since the weather changes so quickly, those beautiful moments when the sun breaks through the clouds happen frequently, but bring more fast film than you would normally carry, since you may run into a few dull days. Incidentally, if anyone recommends a pub as having "great crack", don't run away. It's the Irish word "craic", pronounced "crack", and means "good fun and conversation". Rooms may be chilly in November, so warm PJs might be a good idea. Hope you have a great trip! Pat White