Identify what kind of books you want to publish. As a fledgling enterprise, it's recommended that you start out by specializing in just one area (business texts, romance, cookbooks, travel guides or memoirs), learn everything you need to know about marketing that niche, and then decide if you want to branch out to different genres. Running a publishing company takes a lot of energy (especially if you're doing most of the work yourself). If you spread yourself too thin by trying to diversify too fast, it's going to be hard to do any of the reviewing, editing and formatting particularly well.
Decide who your prospective book buyers are going to be and which publishers they're likely to currently be buying from. To use romance novels as an example, troll the romantic fiction aisle at bookstores and make note of the cover designs, the back cover "hook" copy, the pricing and who the publishers are. Many of the prominent publishers have websites as well as listings in "Writer's Market" that share their submission guidelines. These will give you an overview of what they're looking for, what they're paying, and whether authors need to be represented. Determine how your own publishing company might offer writers something different from the norm.
Research what kind of books literary agents are the most enthusiastic to market. Agents can be valuable allies in sending new authors to your door. A quick and easy place to start is the Agent Query website (see Resources below). If your focus is going to be gardening books, for instance, an agent who specializes in this area will be excited to know that there is a new publishing entity to which she can send her clients' proposals and manuscripts.
Develop a comprehensive business plan that identifies the goals of your publishing venture for the first 5 years, your projected expenses (purchase or lease of office space and storage, equipment, supplies, staffing, membership in professional associations), vendor liaison (printing companies, graphic artists) and your marketing strategy (website, advertising, direct mail, catalogs).
The website of the Small Business Administration (see Resources below) can walk you through the necessary steps of writing the business plan, getting a business license, getting a federal tax ID number, and registering your corporate identity with the Office of the Secretary of State.
Visit area print shops to determine which one offers the best rates and can accommodate the publishing needs of your new company. The printing aspect of the business is going to be your most expensive investment.
Identify your distribution mechanism. For instance, do you plan to use a national distributor or strictly hawk your merchandise through your own website, direct mail/catalogs or through local bookstores? Websites such as Writers-Publish (see Resources below) can help you find the right match for your needs.
Purchase a block of ISBN numbers to assign to new releases. This can only be done through the ISBN Agency (see Resources below). This identifying code is what will enable bookstores and libraries to stock your titles.
Design a professional website that introduces your publishing company to prospective authors. Identify the types of projects you are looking for and whether you pay an advance. Explain your royalty structure (usually 10 to 15 percent of sales) and how involved you expect your authors to be involved in hyping their own books. Instruct potential authors insofar as whether you only want to see a query letter, a synopsis, sample chapters or the full manuscript.
Send agents the announcement about the opening of your new publishing company. Submit your company's profile information to publications such as "Writer's Market" so your listings can be included in future editions.
Hire readers and editors who are just as passionate about the craft of writing as you are.