The first thing to do is to outline all of the parts found in a traditional business plan: Company Overview, Industry Analysis, Market Analysis, Competitive Analysis, Marketing Plan, Operations Plan and the Financial Plan. Next, outline the Executive Summary, which features the market need, unique products and services, sustainable industry, the large and growing market, strong value proposals, experienced management team and financial projections. [Note: Pay particular attention to the sections of most interest to potential investors]
Once you've listed the business plan and executive summary, add the subheadings and the information for each section. At this early stage, your content can be in the form of relevant questions (which can be subheadings on their own) which, when answered, will begin to build each section of your plan.
You should set apart time to sit down (whether on your own or as a team) and come up with ideas about the business. Make an outline for the meeting, and attempt to fill in any holes that might exist in your business idea through brainstorming and discussion.
The outline that you prepare before the meeting should be adhered to, and will serve to both start conversation and build your "line of attack".
Searching on the net is a free and easy way of collecting information and data. Finding information on your particular market might be more of a challenge (not to mention time-consuming), but any research into the scope and activity of your market is well worth the time investment.
If you are serious about your business and want the best business plan you can get, then you might consider purchasing a market research report or hiring the services of a marketing firm. This could very well increase your expenses, but the benefits of a dynamic and successful business plan could prove to be priceless further down the road.
Set a strict writing schedule on your calendar and stick with it. Writing a business plan takes focus. Tackle each section in blocks of time. For example - 4 hours for the competitive analysis, another 4 hour slot for the industry and market sections, etc.
A complete business plan can be finished in 25-30 hours. If you dedicate 8 hours a day you can be finished in four days. From here, you can set aside time for revisions and suggestions from your management team.