Malcolm Storey's online field guide - an excellent site full of pictures of all groups of wildlife

The Wildlife Trust for Berks, Bucks & Oxon (BBOWT) - the local Wildlife Trust

British Entomological & Natural History Society (BENHS) - the leading society catering for serious entomologists

Amateur Entomologists Society (AES) - pretty obvious really - they have a junior wing too called the Bug Club

Butterfly Conservation (BC) - the leading national organisation campaigning on conservation issues related to bufferflies & moths

UK moths page - and excellent site with pictures of most species