By now you know Twitter Bootstrap, but also consider using the Sass versions of Zurb’s Foundation, or Thoughtbot’s Bourbon and Bourbon Neat when building your static site.
from http://foundation.zurb.com/develop/download.html
Default CSS
This version of Foundation includes
smart defaults and doesn't require Sass or any other tools. You would
use this to build on top of Foundation with vanilla CSS.
Download Foundation CSSCustom CSS
You can customize your build of
Foundation below to include or remove certain elements, as well as to
define the size of columns, colors, font size and more.
Customize FoundationSass
Foundation is built using SCSS, and
you can work with it in the same way. To get Foundation using Sass,
check out the instructions on the Install documentation page.
Install Foundation SCSSfrom http://foundation.zurb.com/develop/download.html