Cover all bases. Before embarking on your plan it is a good idea to undertake some research in to what a professional business plan should include. You can then use this as a check list to make sure you have covered all the relevant areas. Sections of the business plan should include information on the company, the product/service market, competition in the field, management team, marketing strategy, operations and financials.
Once you have done all this you should have a complete and detailed professional business plan. The most important thing to remember when developing the plan is to see it as a living document and include specifics regarding dates and specific responsibilities. Your plan will need constant reviews and updates and things change so expect it to be a work in process for a good stretch of time. It will all be worth it in the end, a well-written plan will help ensure that the business is fully focused on what is required to achieve the company's goal.
Business plans may target changes in perception and branding by the customer, client, taxpayer, or larger community. When the existing business is to assume a major change or when planning a new venture, a 3 to 5 year business plan is required, since investors will look for their investment return in that timeframe.
To stay clear of any legal involvement, both parties concerned must comply and honor all agreements made. Since the loan agreement serves as a contract and legal documentation, a violation of the terms and agreements can lead to a legal case and the written agreement can function as proof in court.