Sustainable Agriculture Research and Education
This organization offers a wealth of information and resources on sustainable agriculture - as well as grants for farmers. There's a whole section here for farmers and producers, including helpful publications such as Building a Sustainable Business: A Guide to Developing a Business Plan for Farms and Rural Businesses.
ATTRA - National Sustainable Agriculture Information Service
Funded under a grant from the United States Department of Agriculture's Rural Business-Cooperative Service, the National Sustainable Agriculture Information Service is a great resource for information on field crops, soils and compost, farm energy, organic farming, livestock and more.
Just learning what permaculture is? Stop in here and soak up key concepts and learn about demonstration projects, learning sites and courses.
Slow Food USA
The Slow Food movement emphasizes sustainable practices in growing food and feeding people. It's a great place to learn more about sustainable food production. Here you can find information on endangered heirloom varieties of livestock and food you might want to grow in the Slow Food Ark of Taste.