Two I like:
Ken Rockwell's Nikon Reviews and Tutorials - kenrockwell.com
Kinda heavy on the begging, but great advice for us Nikon users.
For the Canon bunch - photography on the net Yes, it's a forum, but like V7n, it's full of sage advice. photography-on-the.net/forum
For my forays into product photography, I really like all of the DIY Photography sites. I bookmarked several when I was building my tabletop lightbox.