Been over to Ireland a few times and would definately agree with all the posts before. The west is the most scenic but I would find it hard to name a favorite. I have always used the B&Bs for my trips & tend to move on day by day use the tourist offices to find accomodation in your destination area always worked well for me. The roads are generally good but as someone else mentioned watch out for loose gravel, they seem to do the whin dust on sprayed tar routine to tpop dress the roads in a totally random manner. the food is generally good and the hospitality (particularly in the small towns & rural areas) is brilliant. I love the relaxed ways the Irish go about things & the fact all of the small towns & villages still have their own identities, the big chains haven't really got the same grip as they have here in the UK.
Oh, and they really like their stout

has anyone told you that? Don't forget to try as many different ones as possible in as many bars as you can manage (not while on the bike of course).
I tend to book somewhere for my first night via the internet then just follow the front wheel for the rest of my trip, makes an interesting tour.
Whatever you do you will enjoy the Emerald Isle, its nearly as good as visiting the West Highlands of Scotland
D