Starting an IT consulting business is a process that follows all of the steps we laid out here. The only difference is the focus on a specific industry or field of work (computers).
That said, getting a degree or certification in Computer Science, Computer Engineering, Software Engineering, or something similar is a start. The steps to developing and scaling your business as a computer consultant follow the path we've laid out here. You'll just need to adjust the details to suit the needs of an expert on computers.