Here i am trying to amalgamate a list of circuits and airfields which are used for racing and trackdays to help you get info.
I will add info as i get chance. If you have info to add to here, please pm me.

Anglesey Circuit
http://www.angleseycircuit.com/

Bedford Autodrome-
http://www.bedfordautodrome.com/

Brands Hatch
http://www.motorsportvision.co.uk/brands-hatch/

Bruntingthorpe
http://www.bruntingthorpe.com/

Cadwell Park -
http://www.motorsportvision.co.uk/cadwell-park/

Castle Combe -
http://www.castlecombecircuit.co.uk/

Croft Circuit -
http://www.croftcircuit.co.uk/

Donington Park -
http://www.donington-park.co.uk/

Goodwood-
http://www.goodwood.co.uk/

Knockhill
http://www.knockhill.com/

Mallory Park -
http://www.mallorypark.co.uk/

Oulton Park -
http://www.motorsportvision.co.uk/oulton-park/

Pembury
http://en.wikipedia.org/wiki/Pembrey_Circuit

Rockingham -
http://www.rockingham.co.uk/

Silverstone -
http://www.silverstone.co.uk/php/home.html

Snetterton -
http://www.motorsportvision.co.uk/snetterton/

Three Sisters -
http://www.three-sisters.co.uk/

Thruxton
http://www.thruxtonracing.co.uk/

Aintree
Barkston Heath
Waterbeach
Woodbridge