Check out their web site NGroadracing.org
They are based around central and West UK. Tracks include Donington, Darley Moor (Derbyshire), Pembury (South Wales) and Keevil (Wiltshire)
They are a good club for beginners. Compedative but not too serious. You dont see guys turing up with 2 spare machines unlike some of the more serious/profesional clubs.
Check out the ACU.org.uk site for other clubs around the UK.