About.com / Parenting Adolescents  and About.com / Parenting K-6 - Both these sites offer comprehensive listings.  At Parenting Adolescents, you will find a wealth of information on pertinent topics such as gifted teens, financial aid, menstruation, eating disorders - too many topics to list them all.  Parenting K-6 focuses clearly on the elementary school years with sites for education by subject, discipline, arts and crafts, feelings, problem solving and many more subjects relating to this age group.

All Kinds of Minds - The site of Dr. Mel Levine. Provides invaluable insight into how learning can be impacted by individual learning styles.  Dr. Levine discusses learning disabilities and how personality and temperament can effect a child's ability to learn.

Encyclopedia of Mental Health - Shyness experts, Lynne Henderson and Philip Zimbardo discuss in detail the causes and symptoms of shyness.

ERIC Digest - Working with Shy or Withdrawn Students - Advice for teachers on how to work with shy children in the classroom. 

Kinderstart - A new site with hundred of resources for parents on issues ranging from sibling rivalry to medical and emotional health.

Manners and Etiquette - From familyeducation.com, this site could win the "everything you always wanted to know" category for etiquette, table manners and sportsmanship.  Great links to other  sites.

Painfully Shy - Experienced professionals who specialize in anxiety disorders provide useful insights and tips for adults, children, parents and teachers.

Parentsoup - While not specializing in the issue of shyness, most parents should find useful information at this site.  Providing communities for several age groups (from pre-pregnancy to teen years), expert advice, chat rooms and shopping.