There are a fair few Canine Societies in the county but it's pretty big so travel time might be prohibitive to some of them. Whereabouts in Devon are you?
There is also Tavistock & Disctrict Canine Society but I can't see where they hold their training. They have a show coming up in October so you could try ringing the show sec for info about their ringcraft. Schedule here
Okehampton is your nearest, but as its a very small hall I personally feel its better suited to smaller breeds. What breed is it? I can prob help a bit with local venues as you are near to me :)