Developing a Business Plan can be one of the most important and useful exercises involved in the development of new farms. Not only is this process useful in helping to understand and articulate what the farm enterprise will look like, it is also important in building a farm development plan that is economically sustainable, and can be essential in procuring the necessary funds with which to purchase land, equipment, and other resources necessary to get started.
The New England Small Farms Institute's Growing New Farmers Program helps to answer the question: Do I need a Business Plan for my Farm? by providing advice and resources related to this question at: http://growingnewfarmers.org/main/for_new_farmers/new_farmer_q_and_a/business_plan_for_my_farm/
Free Business Planning from the University of Minnesota. “AgPlan,” designed specifically for farms and ag businesses, provides guidance in writing your business plan, offers the option of collaborating with one or more advisors, and allows you to save your planning work online (or print it out). Online software at http://agplan.umn.edu/
And the USDA National Agricultural Library's Rural Information Center offers Small Farm Funding Resources which include documents which assist in the development of a Farm Business Plan at: http://www.nal.usda.gov/ric/ricpubs/small_farm_funding.htm
Each of these resources can be extremely useful for people at all stages of thinking about or planning to start new farms or farm related businesses.