I biked around Ireland for five weeks, having had no previous touring experience and without an itinerary. I was ready to camp, but it turned out I always found a hostel or B & B to stay in. At night, I would pull out a map and choose an interesting looking town as my next day's goal, using castle locations as a loose structure for the overall trip. Met a lot of fun people in the hostels and pubs, and had the time of my life really.
Watch for tour busses, they are eerily quiet and blast past you before you know they are there. Get a mirror for your helmet or handlebar, it will help in assessing whether encroaching cars see you or not based upon their lane positioning.
Have fun and don't be shy when you're out there! Also, remember to take advantage of the huge breakfasts at B & B's when you can.