Even if your best friend owns a top publishing company, giving you an immediate "in", this does not guarantee publishing success.
First, you have to write a quality book that has a clear target audience. And your book must answer a common problem or need that audience shares. Then you have to develop a marketing plan, and stick to it for at least two years.
Let's begin with the process that should commence before you write your first word. Begin by reading A LOT. Read both books you passionately love and books you can't seem to make it past page five. Then figure out what the author did in the book you loved, and what was wrong with in the book you couldn't finish. Write down these points so they are crystal clear to you. Read other people's books for inspiration and to discover what you should avoid as a writer.
The next step is to plan out your book. Narrow down your subject, and then divide it into chapters. Each chapter should address a specific aspect of the problem your book is going to solve. In each chapter, break the specific aspect down into several parts. This will help your readers take in your information a bit at a time instead of overwhelming them with every bit of information clogging up the pages until they feel like they're about to go blind. It's not quite spoon-feeding the information to your readers, but it's close.
The next two steps are obvious. Write your book and then revise it. ...