Here are a few links to some of the sites we use and like:-

 

Brian's pictures at Alamy

http://www.alamy.com/stock-photography/37DE5F67-23FB-431A-9118-CA480B124796/Brian%20Dingle.html

The Royal photographic Society

http://www.rps.org

The RPS Nature Group

http://www.rpsnaturegroup.com