Maaz - Would that be The Approach by Jamie D Grant? It's a great primer on how to get paid performances as a strolling magician, but does not cover really any of the significant aspects of business, as Jamie specifically emphasizes not being a professional magician but using it as a side income (albeit a lucrative one for him).
Aiden Sinclair's lecture was great - he goes through the whole process he had of starting from nothing (fresh out of prison, to boot) and building up to a very successful show at the Stanley Hotel.
Paul Prater has some good points on marketing. I think you can buy his lecture notes on that subject separately, I do recommend them.
Gig Flow is a 28-day long email "course" by Kennedy that helps you develop a working marketing model.
You're also going to want to look into basic accounting/budgeting - until you're very well established you won't have steady gigs all the time, so you need to know how to manage your money for the leaner times.
There isn't a lot in the magic world that teaches the nitty gritty of running a business. Partly, I think, this is because the subject is covered in plenty of books outside of the magic world, and partly, I think, because those who are successful are often guarded and cagey about their systems because they fear competition. These fears are mostly unfounded, but what can you do.
Read books on marketing. The significant difference between a professional magician and an amateur one, is that a professional is able to sell their show regularly enough to make a living. That largely hinges on marketing.