Here are some links to organizations concerned with food safety, justice, marketing, and related issues:
Organizations
Local Harvest
Includes info on local farms, CSAs (Community supported agriculture groups), etc.
Organic Consumers Organization
Monterey Bay Aquarium Seafood Watch – The place to start for info on fish.
Center for Ecoliteracy
The focus is on "Education for sustainable living," with food at the center of that focus.
Chef Alice Waters' Chez Panisse Foundation
This is the organization that began the Edible Schoolyard Project and has an ongoing school lunch initiative.
Just Food (NYC)
One of the many volunteer-based organizations dedicated to "food and justice"; in practice, this often means connecting farmers and their produce with lower-income city folk. They also encourage City Farms.