The Seattle Public Library has been my own personal business school. Since starting my own wedding photography company, Eliza Truitt Photography, three years ago, I've used it for educating myself on all aspects of my business. Doing a quick search at my public library's website there are ten books devoted exclusively to running a photography business. Expand a little to look at books on running a small business and the possibilities are limitless.
Recent business books I've read include The Anatomy of Buzz: How to Create Word-of-Mouth Marketing by Emanuel Rosen and The E-myth revisited: why most small businesses don't work and what to do about it by Michael E. Gerber. I find that in each business book I read there is one nugget that I take and immediately apply to improving the way I run my business.
And the library is great for more than just educating yourself on business. When I need inspiration for an upcoming shoot I often browse the section of art photography books and check out a stack I can pore over at home to get my own creative mind revved up. And all those famous photographers whose names I've heard here and there–I check out books of their photographs from the library to look at and better understand what the fuss is all about. Looking at the portraiture done by photographers 50 or 80 years ago I am often blown away by how fresh their ideas were, and how much I have to learn from their work.
And the best part is that this education was entirely free, which I didn't need a business book to tell me was a wise financial decision.