This book addresses people with a business idea thinking about founding a company. The paper enables those people to write a successful business plan helping them to check the profitability and feasibility of their idea. Furthermore it supports the reader to convince investors, suppliers, customers, employees and themselves to invest time and money in the foundation of this company. The theoretical concepts will enable the readers to understand the importance and the aim of each part of a business plan. The practical examples from the business plan for a student advisory company following each concept will lead over to the realistic design of a business plan. Last but not least, this paper will call the attention of potential entrepreneurs to some problems they may have to solve during their own way of founding.