If you work web design or you work graphic, these are some of the most important links that will make your work easier.

www.webdesignerdepot.com
Tutorials, advice, inspiration...

www.smashingmagazine.com
All the time source of information, tutorials and design ideas.

www.psd.tutsplus.com
Tutorials for Photoshop.

www.designmeltdown.com
Useful links for web designers.

www.csspig.com
Strange name site :), but at the moment one of the best CSS galleries on the internet.