Some links which may be useful:

Woodturning Clubs
Surrey Association of Woodturners - my local club
Cheam Woodturners Association - my other local club
East Surrey Woodturners
The AWGB - the National body
Orchard Woodturners

Snainton Woodworking Supplies
Stiles and Bates woodturning supplies
Interesting Timbers wood supplies
Yandles Woodworking supplies
John Davis Woodturning supplies
Noggin End Metals
MJ Engineering
Black Forest Wood Company
Alec Tiranti Ltd art supplies
Jo Sonjas UK paint supplies

Other interesting/useful sites
Laymar Crafts Woodturning
The Daniel Collection