Having a plan for what you are attempting to acheive is a critical success factor. There are numerous methodologies for creating effective business plans etc.
The best approach I have found is the One Page Business Plan(c) methodology developed by Jim Horan. It has been used by hundreds of thousands of entrepreneurs, businesses and organizations to develop highly effective plans to guide and support successful business growth.
You will be using that approach to develop you plan for the growth of your business.