In reply to rhyswatt:
Shaftoe would be a good bet, especially if you know the area, it can be a bit confusing on your first visit and agree that the rock is pretty rough on the skin!
Another option would be Bowden (Sheep Pen is a great place for newbies), Back Bowden (The boulders offer a good range of easier problems) and Raven's Crag (Great selection of short easy problems at the far end) These area are all close together so can be combined if time allows.
A few points about all these areas, most problems top out which will be a new skill for indoor climbers, get them on short easy things first until they understand how to top out! Also worth pointing out how important clean shoes are on our easily damaged sandstone. Make sure they keep their shoes clean and give them a wipe before stepping on.
Have fun.