You may find that the easiest part is the actual writing of the plan. The real work comes in the data-gathering, which may take you a hundred hours or more, depending on what you already know or have researched. If your new venture is in an area where you've been working, you may already know about your customers, your suppliers, your marketing plan, your organizational structure, your financial and cash flow needs, equipment, inventory, and so on.
Financial Plan - What is the anticipated income? What are the cash flow projections? What is the anticipated budget over the next 3 years? What is the break even point? When is it anticipated to be met? What funding is needed and where will it come from? What funding is currently available? What collateral is available? What is the net worth of the principals, if applicable? Possible Data Sources: accountant; accounting software; Small Business Administration; Small Business Development Center; SCORE; banks; venture capitalists.
One key component critical to your success is scoping the competition. A business plan consultant studies the area where you will be located quite thoroughly. For example, if you plan on setting up a coffee shop on Main Street, or within the vicinity, the small business consultants you consult with will inquire about the number of existing coffee shops and the services they provide.
After doing this, they will give recommendations based on what they find. If there are coffee shops already in place, one recommendation they might make would be to include free Wi-Fi as a way to bring in more customers.