You could try these websites:
http://www.helicopters.uk.com/Training/training.html
and
http://www.flyer.co.uk
The Flyer website is geared towards general aviation in the UK and so will have a link or a list of flying schools.
My advice is to visit all potential schools, I used to drive past one to get to the one I learned with as they were much friendlier and the machines were a lot better. Good luck.