Hi Pottypotter - so many questions, so little time!
For your tuber in a pot you need about 4inches of compost underneath it & about 10-12 inches above it I would say.Most people usually start with just 3 or 4 inches above the tuber & earth it up as the shoots grow. You can grow them in smaller pots with less compost above them but will probably get fewer potatoes out. As for yield from 10 seed potatoes it could be anything depending on the variety, where you plant them etc. Some people just get a few pounds in weight, some could probably get 10 or more, I'm sure I read somewhere about a man getting a couple of hundred pounds of potatoes once from a couple of seed potatoes!