In a web browser: Browse to oshpark.com, select "Get Started Now", then "Select a file on your computer". Select northstar.zip from the repo. Fill out the name, contact and billing information.
Order the parts. Current BoM Shopping Cart (for three boards) @ Mouser: FIXME
Solder it up!
All files are licensed CC-BY 3.0 unless otherwise marked. Full text of the CC license is available in LICENSE.txt