#BeagleBone Black: Burning an OS image to a microSD card and installing
Your BBB may already come with an OS installed. Check this. If this is good enough for you, you're done.
We are currently installing Debian Jessie 8.3 at the Exploratorium, except for Eyal who has a Wheezy install image for reasons of his own.
Check to see whether we already have a current installation image on a MicroSD card for you to use. If not, burn your own. Note that this can take up to an hour of your time or more if things don't go as planned.