Kilkenny isn't a large town to start with, and the hostel has an excellent location just a few blocks from the center of town. From the intersection of Rose Inn Street, the Parade, Patrick Street, and High Street, just west of the bridge in the center of town, head north on High Street about five blocks or so and it turns into Parliament Street. The hostel is on the right. If you come to a "T" intersection with Dean Street and Vicar Street, double back about a block.
The hostel reception is open until 11 p.m. If for some reason your arrival will be even later than that, they are flexible and will make an effort to accommodate your situation. The kitchen, common rooms, bedrooms, and bathrooms are all OK, but the one downside is that the kitchen and common rooms are locked up from 11 p.m. until morning. If you're a fan of hitting the road early, perhaps bicycle touring or the like, you may want to reconsider storing your food in the kitchen the night before you depart. There is also no breakfast served at the hostel.
Kilkenny has a well-earned reputation for per capita partying, and the hostel is certainly no exception. Odds are you will have to deal with at least one fellow guest who's either had too much or is dealing with the after-effects. There are exceptions to every rule, of course, and more philosophical students can be found visiting the hostel, too.
For the opportunity to visit a great party town with a lot of history as well, the Kilkenny Tourist Hostel is a decent overall value for the budget-minded traveler. If you're coming from Dublin, hostel rates in Kilkenny will seem like a steal! Otherwise they'll seem pretty normal compared to other parts of Ireland.