Teens Health- Diseases and Conditions:
From asthma to ulcers, this section is loaded with articles about diseases and conditions that can affect teens. Look here for health information and resources for yourself or someone you care about.
http://kidshealth.org/teen/diseases_conditions/

Teen Health FX:
This site is a great online resource for any and all questions regarding your health, your relationships, your body and your sexuality.
http://www.teenhealthfx.com/

BAM: Body and Mind!:
This site is the place to find advice on your body and your health.
http://www.bam.gov/sub_yourbody/index.html