Here's one with a lot of good inspirational photos:
http://digitaljournalist.org/issue0309/lm01.html
A very informative site for beginners and professional alike. There are a multitude of sites under photography tutorials.
http://www.apogeephoto.com
You may find this site helpful with photographic discussion, competitions, gallery etc.
www.digital-photo-forum.com
Top Sports Photos
http://sportsillustrated.cnn.com
Useful, tips on tecniques etc.
www.shutterbug.com
Information here on histograms and much more
www.luminous-landscape.com
Useful information and examples and a few lessons on portrait photography
www.montezucker.com
www.Apogeephoto.com
It is a web magazine of photography. Have a look.
http://www.planetneil.com/index.html
Neil has some good technical writing on his site. Have a look at this flash pgotograph and RAW work flow.