Any website from websites for amateurs to websites for pros can qualify.
You might also want to have a peek at The Guide to Sound Effects at http://www.epicsound.com/sfx
Here's a list of 10 Essential Sound Design Blogs. Not all of them are about tips and tricks. But it's a good start in the right direction.
http://designingsound.org/2009/06/sound-design-essentials-websites/ ;-) I made that list some time ago. Maybe you could find useful info there.
These aren't so much about designing sounds as sound designers, design theory, and stuff that could help to go pro.
How several sound guys got their start: http://www.hollywoodreporter.com/hr/search/article_display.jsp?vnu_content_id=2090280
Mix Magazine's article on breaking into the audio industry: http://mixguides.com/education/articles/breaking-in/
Some videos about sound designers: http://www.recordbetteraudio.com/recording/sound/design.php
Sven's entire site: http://filmsound.org/
wow! this site epicsounds is awesome place to get started with sounddesign!!!!
Ask any question here at Social Sound Design and you'll get some excellent advice from any number of pros.
Just don't ask which microphone or recorder you should buy when starting out! Think we've had that one a few too many times... :-)