http://www.peachpit.com/articles/article.aspx?p=369225 Semantic design
http://www.webdesignfromscratch.com/web-2.0-design-style-guide.php Web 2.0 Design Guidelines
http://www.hesketh.com/publications/progressive_enhancement_paving_way_for_future.html" Another view of progressive enhancement
http://www.csszengarden.com CSS Zen Garden site
http://www.mezzoblue.com/zengarden/alldesigns/ Links to all CSS Zen Garden designs
http://www.addedbytes.com/cheat-sheets/css-cheat-sheet/ CSS Cheat Sheets
http://www.addedbytes.com/cheat-sheets/html-character-entities-cheat-sheet/ HTML Character Entities Cheat Sheet
http://www.smashingmagazine.com/2006/10/30/cheat-sheet-round-up-ajax-css-latex-ruby/ Collection of Cheat Sheets
http://www.allwebdesignresources.com/webdesignblogs/graphics/30-css-cheat-sheets-quick-reference-guides/ Collection of Cheat Sheets
http://www.cheat-sheets.org/#CSS Directory of CSS Cheat Sheets
https://addons.mozilla.org/en-US/firefox/addon/60 Web Developer add-on for Firefox
https://addons.mozilla.org/en-US/firefox/addon/1843 Firebug add-on for Firefox
https://addons.mozilla.org/en-US/firefox/addon/2104 CSSViewer add-on for Firefox
http://webkit.org/blog/41/ Web Inspector allows you to view page source; just right click on an element, or hold Shift + Control.
http://www.westciv.com /xray/xray_more.html Xray tool for CSS analysis:
http://jigsaw.w3.org/css-validator/ CSS Validator [file must be on a server]
[You can also validate using the Web Dev tools]
http://www.smashingmagazine.com/2007/05/10/70-expert-ideas-for-better-css-coding/ Workflow and good practices
http://www.smashingmagazine.com/2008/02/21/powerful-css-techniques-for-effective-coding/ more ideas for better coding
http://css-discuss.incutio.com/?page=DesignInspiration Well designed pages
http://www.cssbeauty.com More CSS design pages [see 'Gallery' for images, and home page for examples. techniques in CSS3]
href=http://cssvault.com More CSS design pages
http://www.sawmac.com/missing/css/tutorials/ Download the book chapter tutorials from “The Missing Manual” book
http://www.smashingmagazine.com/2009/01/14/web-design-trends-for-2009/ Web Trends for 2009