The document outlines 9 things that were not told to the author about starting a business. It advises to not generalize, prioritize work flow, meet people in person, understand that sales are important, technology is not the only part of a product experience, sell the current version and not future promises, learn from mistakes, hire the right people, and tell an honest story to potential customers. The document was written by Hjálmar Gíslason for Nerd and provides a link to presentation slides about the 9 points.