Circles enables users to organize contacts into groups for sharing information.

• The Circles: Dividing, Nesting and Prioritizing (available in multiple languages) by +Ahmed Zeeshan.
• How to Manage Your Google+ Circles Without Going Crazy by G+ Insiders Guide.
• Downside to Letting Everyone In by M Sinclair Stevens
• Circle reordering (includes video) by +Brett van Zuiden.
• How to Sort and Manager Circles by +Kelly Clay via Lockergnome.com
• Google+ and Reciprocity, or “Why Aren’t You Following Me Back, JERK?” by Christina Trapolino
• Designed for Asymmetrical Relationships: Avoiding the Echo Chamber by M Sinclair Stevens