I also googled 'dog training class' and then my county, but I found emailing the Kennel club on the address given on their page was the best - they sent me a list of classes, one of which was just a couple of miles away
I spoke to a couple of different trainer's and you can generally watch their classes to see what you think. The first one I spoke to didn't feel right, but the second one was much more what we were looking for. A gut instinct really.
Defnitely worth going to see the class to see if it is what you want. I went to some at my local vets and they were awful, but you didn't get the option to look before you went, which I regret. I then went to look at another class but it seemed too strict (lots of choke chains and not enough treats for my liking), and am soon starting some that have been recommended to me by someone who's been going there for nearly 2 years.
I found it by Googling dog training classes in my area, and then I rang round to see which ones I could visit frst - if they said no I struck them off the list immediately!
It's worth finding out also if they have to have had a kennel cough vac before you can go - some classes insist on this, others don't.