The websites listed here offer offer a variety of free information about attention deficit disorders.  Most specialize in issues concerning children and adolescents; some focus more on adults.  Many are sponsored by ADD support and advocacy organizations and provide detailed, downloadable information that has been evaluated and approved by a professional advisory board; others are less selective and may include reports that are not adequately supported by scientific research.  Some list contact information for local support and advocacy groups concerned with attention deficit disorders.  Many have links to related organizations, and all are nonprofit.