I am building a Drupal 7 site, and I am quite new to Drupal. I want to assign each authenticated to a group which I define myself, for instance "friends", "family", "coworkers", "mortal enemies" and so on. I want the content access permissions to depend on this group, so that my friends and family are allowed to see all my images with cute kittens, whereas my mortal enemies should only have access to my archive of taunts and elaborate verbal abuse.
Any suggestions?