If that's your goal, definitely check this one out. Each one also contains a marketing plan and executive summary template.
My recommendation would be to stay as cost-effective as possible. Here's a list of articles and resources that should help get you going:. It might even lead you to kill off aspects of your business before investing too much time or money in them.
That doesn't mean you have to bust out Word and start the plan from scratch. A template is great--you probably aren't doing anything that hasn't been done before, so it provides a proven structure for your plan. Why is this the right time to enter this market?