http://www.smashingmagazine.com/
http://designmodo.com/
http://designm.ag/
Twitter (follow the right people)
http://caniuse.com
http://uptodate.frontendrescue.org/
http://css-tricks.com
http://www.hongkiat.com/blog/css-snippets-for-designers/
http://www.cssplay.co.uk/
http://codepen.io/

Just a few of the Creative Web Group use, not all relevant to your question, but resources either way!

David