Marketing - How is the product or service priced? How will it be distributed? How will it be promoted? Will it be promoted by the venture or an outside agency? What agency? How have you determined what amount to set aside for marketing? How have you determined product or service forecasts? Possible Data Sources: on-line searches; Amazon; local outlets; trade journals; industry attorneys & accountants; salespeople.
There are a number of ways of going about the process of writing a good business plan. One of the most tried and time tested ways that works well is using a business plan template.
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.
The best place to find web templates is to search on the Internet. There are many sites to search templates and they frequently provide good supplementary details and technical support. You can regularly see a sample of the template you are taking into consideration.