Webmonkey - A wonderful resource for website developers. Contains many tutorials and examples.
A List Apart - A List Apart is written by the community it serves: designers, developers, architects, producers, project managers, and assorted specialists.
W3Schools - W3Schools is a web developer information website, with tutorials and references relating to web development topics such as HTML, CSS, JavaScript, PHP, and SQL.
CSSZenGarden - The CSS Zen Garden is a World Wide Web development resource. The goal of the site is to showcase what is possible with CSS-based design.
Tech Soup - TechSoup is a comprehensive source of technology information and discounted software just for nonprofit organizations. Help yourself to everything inside -- it's all served up by people who know: our nonprofit technology staff, experts in the field, and your own colleagues.