Sassaparilla
Sassaparilla (Sass-aprilla) is developed by the helpful guys over at fffunction, who also produce a number of other helpful web tools for front end developers.
This tool provides you with a default set of Mixins, @includes and $variables to get you started with your responsive project. They give you a set of typographical rules that use EM’s and will fall back to pixels when required and maintain a hierarchy and flow for your content.
If it’s your first time using a preprocessor then this will give you the understanding of the common approaches to laying out your CSS in an object orientated way.