Health: Kid's Health

http://kidshealth.org/ Billed as the most accessed site for kid's health, this is a treasure trove of information for parents, kids and teens.

Health: Health Finder

http://www.healthfinder.gov/kids/ Health Finder Kids. Another compilation site with good information provided in a kid friendly format. Includes topics such as safe surfing and cool and uncool (things like drugs and alcohol). There are also some health related games to get the information to kids in a fun way.

Health: Health and Human Services

http://www.hhs.gov/kids/ Health and Human Services page for kids health. A good general site for children with health related questions, or for discussions with parents.