To do this, you're going to have to come up with both a marketing strategy and a marketing plan.
What's the difference between a marketing strategy and a marketing plan?
The marketing strategy is shaped by your overall business goals. It includes a definition of your business, a description of your products or services, a profile of your target users or clients, and defines your company's role in relationship to the competition. The marketing strategy is essentially a document that you use to judge the appropriateness and effectiveness of your specific marketing plans. The CCH Business Owner's Guidebook has an excellent explanation and checklist that you can use to work through your marketing strategy.
To put it another way, your marketing strategy is a summary of your company's products and position in relation to the competition; your sales and marketing plans are the specific actions you're going to undertake to achieve the goals of your marketing strategy.
The marketing plan, then, can be thought of as the practical application of your marketing strategy. If you look at my article, "Writing The Marketing Plan", you'll see that the marketing plan includes details about your business' unique selling proposition, pricing strategy, the sales and distribution plan and your plans for advertising and promotions.