http://www.2createawebsite.com/build/hex-colors.html — put in Hex or RGB values and view color
http://meyerweb.com/eric/tools/color-blend — this will give ranges of colors between two.
http://www.web-source.net/216_color_chart.htm — This is a table which has a nice flow of colors
http://www.somacon.com/p142.php — This has a pretty extensive list of CSS colors.
http://www.321webmaster.com/hex-to-rgb.php — RGB to HEX color converter