Soldeu would be the best place to go if you want access to the whole area, but as novices I doubt you will explore very far, so Arinsal would be perfect. It has high recommendations for tuition for english speaking skiers. Plus up the road is Arcalis, wonderful place for a day out.
Pas is Ibiza on snow, its taken over from Sauze in Italy as the noisy party town for many british skiers. Don't expect much sleep if you go there, plus you are stuck at one end of the ski area, and if you want this area then head to Soldeu, more up market and chilled out. I only had 4 days in Andorra but worked out Soldeu would be the best base for intermediates, but as your other half has only been once before, he isn't likely to be in a position to ski around a large area I imagine.
Arinsal is ideal.
Don't forget to have an evening at the spa centre in La Vella.