Rights-Free and Rights-Light Media & Content: Licensing Images
Adding a Creative Commons License to Flickr Photos
To attach a Creative Commons license to your Flickr photo, go into the single photo, scroll down to Ower Seettings, click Edit, and then select the Creative Commons option from the "Set a license for this photo" pop-up menu. Read full insructions here, including how to set a default license for all of your photos.
Creative Commons licensed video by Flickr user Colleen Greene.