I would also contact your local SBDC office for free advice on business planning and starting a business. SBDCs are funded by the SBA and are an excellent resource. You can find your local SBDC here: http://www.bplans.com/sb/

Finally, I also suggest contacting your local SCORE office. SCORE is another SBA funded organization that provides free business coaching and will help you write your business plan. They also have many resources available to help you. You can find your local SCORE office and ask questions online here: http://www.score.org

Good luck!