Kyle, A business plan is really a working description of a machine that you will use to create wealth for yourself. In it, you start with your raw materials - your target market (who they are, what they are looking for, what are the key buying patterns, etc). Then you look at who's going to "share" that market with you - your competitiors. What is your unique selling proposition that will allow your target market to favour you instead of the competition? Next, how are you going to reach your target market so that YOUR unique selling proposition is in front of them? Once they reach out to you, what is your selling process that allows you to conclude an agreement with them? This selling process includes things such as presentation materials (portfolio), business cards, brochures, price sheets, contracts, licensing forms, release forms, and so forth. Part of any business plan is to have numbers that define the size of the market, the market share you expect to get, the number of transactions you need to have to cover your basic operating costs, your selling ratio, and projections of the average revenue, cost of sales, expected gross margin, overhead contribution, and expected net profit.
The business plan will cover the production systems- the tools and equipment you will need to deliver to the customer what you have contracted to provide. This includes (in the case of photography) camera equipment, lighting equipment, computer equipment for processing and image storage, printing (maybe), various licensed copies of software that you will need. It also includes (if appropriate) the place where you will meet clients, have a studio, have your administrative office, etc. The business plan should cover the production flow so that a reader will understand how you will make the production process work, and the assumptions you are making about how much effort/time is taken up with each step.
The business plan will cover the administrative aspects: how you will manage the books, maintain the necessary records for tax collection and remittance, maintain your prospect and client records, daily calendar (to-do lists, appointments, regulatory deadlines), cover your potential liability with appropriate amounts (and types) of insurance, and show a prospective lender, partner, or advisor how you will manage the business.
Probably the most important in the end, is the financial analysis, starting with your overhead projections, and working through the cash-flow requirements (more small businesses go bankrupt from cash-flow management issues than any other), showing how the financial assets will be applied to generate a profit. If you don't have the money to invest in the purchase of your production tools, what kind of loans are you looking for, and what kind of payback can you demonstrate?
If you plan to hire people, there will be a section in your business plan about the human resources (recruitment, qualification, training, pay policy, termination policy, regulatory and statutory compliance, etc.).
Your business plan is not someting to do once and then put on the shelf - it should be a working document, updated often, with the key assumptions tested with actual operational data. It is your operating manual of how you will build this machine to generate wealth.