SHAPE America (Previously know as AAHPERD)
This is the National Physical Education Associations website which has information on professional development and standards/ guidelines on physical activities, physical education, and health education.
This is the California Association website for physical education, health, recreation and dance that can be accessed by professionals and future professionals. You can find information on workshops, conferences, legislative issues and standards for California.
Project Alert - Lesson Plans
This website has many great lessons that can be taught at grade levels from 6-12. It also provides videos that support individual lessons. I've used their lessons with 7th graders and utilized enough material for a 8-week unit on health issues.
American School Health Association - Members receive access to the Journal to School Health where articles can be found about Health and Physical Education.
This website offers health education for teachers and school staff covering a wide range of age appropriate topics taught by professionals.
Teachers.net