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.
James J. Hill Reference Library (jjhill.org): One of the nation's premier business libraries to bring you FREE and affordably priced tools and resources you can use to create a better business plan based on relevant and credible data.
Millions of entrepreneurs, be it first-time owners of small and medium start ups or Fortune 500 business conglomerates, use this program and consider it to the best business plan template generator on the open market.
But your idea may be so new that you may also need to talk to potential customers, host some focus groups, talk to an ad agency, or maybe even make a prototype and float it past some people. Be prepared to spend the time. Remember, it's not about the Plan but the Planning.