I know that the above two posts are probably spam, but I thought I'd add some great links for some cinematography websites:

http://www.theasc.com/

http://cinematography.com/

http://reduser.net/forum/index.php

http://www.deakinsonline.com/forum2/

http://www.icgmagazine.com/wordpress/

http://blog.fdtimes.com/

Enjoy!

(As a side note, some well known cinematographers contribute to a few of these sites/forums like David Mullen, Eric Steelberg, and obviously Roger Deakins on his own site.)