To develop you must have the following tools installed and added to you PATH variable:
Nodejs (NPM)
Git
Sass (Ruby)
After this you will have to execute the following commands in the source directory:
npm install -g grunt-cli
This will install Grunt on the command line
npm install -g bower
this will install Bower on the command line
npm install
This will install all the npm dependencies for the project
bower install
this will install all the static assets for the project
After this you can run the command grunt serve
this will start a server and point the brower to localhost:9000