If you're not sure whether you should operate as a free-agent practitioner or a "go-it-alone" business, Bruce Judson's free 204-page online book, Go It Alone!, does a good job of laying out the differences between the two. Here's a brief excerpt.
"Go-it-alone business is not simply a fancy term for a free agent or a freelancer. These businesses provide their founders with far more stability than freelance work and more personal rewards than franchising. These entrepreneurs are building a substantial asset. They have control of their own destiny. In difficult economic times, free agents or freelancers are typically in the extraordinarily frustrating position of waiting for the phone to ring. In contrast, go-it-alone entrepreneurs always have a focus for their energies and an asset that will provide them with an income stream.
Moreover, freelancers, free agents, and many small-business owners typically work on an hourly or daily rate, or they charge by the job. In all of these cases, they depend entirely on what they can produce as individuals, and their earnings are tied to the clock. They have not established a business system that allows them to magnify or leverage their skills. As a consequence, their earnings are inherently limited. Go-it-alone businesses don’t suffer from this income constraint."