Seek good writers and editors. Quality will be the key to earning credibility in the publishing industry. It is crucial that writers and editors know the mission of the publishing house and how their jobs fit into that mission. Get online and read blogs and other writings that will compliment the publishing house that is being created and seek the individuals who created them.
Consult with experts. This can be as simple as reading everything available on publishing. Dan Poynter, for example, has been in the industry for several years and provides very practical information to publishers about starting and maintaining a business. Independent publishing is a very giving community. Find a a potential mentor and engage them.
Determine a niche. The publishing industry is wide open. Determine what the market is in need of. Is there a deficit of Indian themed fiction? Is NASCAR lacking coverage? Combine interests with market deficits and develop a marketing plan to address it.
Get the necessary permits to start a business. Publishing houses often start as a one man or one woman show. Determine the best company structure for the business and make sure all licensing for the business is acquired.
Find the start up cash. This will depend on the desired growth for the business. Building a publishing house one book at a time is definitely an approach to take and will take a lot less cash. Getting several books going simultaneously may required advances to authors, payments to printers and cash to implement marketing plans and book tours. Decide how the business will grow and go for it.