Links to other Internet macro photography sites; and others of interest:
Plonsky Photography - The doyen of internet digital macro photography
Galerie Macrophotographie - Belgian photographer specialising in macrophotography
Insect Macro Photography, Hector Niam - Beautifully composed insect macro shots.
PBase.com - has some excellent macro photography and nature portfolios.
Books on insect identification have been superseded by online services; two examples are listed below:
Spiders of NW-Europe - The most comprehensive site on spider identification
Bug-Net - Online insect identification, which, rather frustratingly, supports only Netscape.