To install dependencies, assuming that you already have installed node, npm and ruby at least.

Check what gems are installed with gem list should be, at least,

sass (3.4.13)
scss-lint (0.37.0)

if not, install or update sass and scss-lint

Check if bower is available with bower -v if it is missing, install it

globally with npm install -g bower

Check if gulp is available with gulp -v if it is missing, install it

globally with npm install -g gulp

Gulp tasks, try gulp help and it will display all availabe tasks with a description.

Main tasks:

gulp default
gulp dist
gulp dist --release

Default task include the following tasks 'sass-lint', 'jshint', 'sass', 'vendor-scripts', 'scripts' and 'watch'.