Here are some helpful links from the Orange County Designer Meetup from 3 March 2014.
Sass – Sass is the most mature, stable, and powerful professional grade CSS extension language in the world.
Bourbon – A simple and lightweight mixin library for Sass.
Neat – A lightweight semantic grid framework for Sass and Bourbon.
Bitters – Scaffold styles, variables and structure for Bourbon projects.
Emmet – A plugin for many popular text editors which greatly improves HTML & CSS workflow