CSS - Resources

css

http://caniuse.com/
http://westciv.com/iphonetests/

http://codepen.io/picks/1

http://www.fontsquirrel.com

Sound:
http://raisedbeaches.com/octave/
http://rcptones.com/dev_tones/

Color:
http://html-color-codes.com/
http://www.computerhope.com/htmcolor.htm
http://www.colorhunter.com/
http://www.cssjuice.com/25-popular-color-scheme-and-palette-generators/
http://bz.var.ru/comp/web/js/color.html - Online Color Calculator

Creating a compatible font stack:
http://www.cssfontstack.com/
http://awesome-fontstacks.com/

Downloadable fonts:
http://www.smashingapps.com/2012/06/20/massive-collection-of-free-thin-fonts-to-download.html

Optimizing Images:
http://imageoptim.com/
http://www.splashnology.com/article/how-to-optimize-png-and-jpeg-without-quality-loss-part-2/2568/ - How to Optimize PNG and JPEG without Quality Loss. Part 2

UI Patterns

Unit conversion:
http://pxtoem.com/
http://riddle.pl/emcalc/
http://convert-to.com/446/pixels-px-to-em-conversion.html

Other:
https://code.google.com/p/closure-stylesheets/

References:
http://www.w3schools.com/css/css_reference.asp

Sites that cover CSS:
http://2012.dconstruct.org/
http://css-tricks.com/
http://css-tricks.com/video-screencasts/
http://www.csszengarden.com/
http://www.w3.org/Style/
http://www.alistapart.com/topics/code/css/
http://www.456bereastreet.com/lab/ - The CSS, HTML, and JavaScript Lab