The best way to build something is to start with a model. Mentorship is the most powerful force for success in any arena, including business.
Here are the mentors I recommend, by niche:
Fitness - Two-Brain Business (which I own)
Contractors - Profit for Contractors
Dance Studios - Dance Studios of America
Salons - High Performance Salon Academy
Software As a Service - SaaS Academy
Other Businesses: 90-Day Year Program