It's very easy.
I did a Google search for "free website," chose a hosting company (wix.com), chose a template, put in some words and pictures, chose a business name and I was open for business in about 45 minutes. My "company" quickly became Google-able through this blog, and will probably have its own Google link in a day or so.
(above) Just as Lulu and other companies advertise "free self-publishing," it's also possible to form a self-publishing company for free. All I needed is an email address, and accounts with Paypal and CreateSpace. I'll let the authors do the writing, editing and designing, and offer various services for additional fees. Books will automatically be available for sale.
Here's the website for 99 Buck Books. Will I defeat Outskirts Press and CreateSpace? Will 99 Buck Books get bought by Author Solutions or Amazon for millions of dollars? Will I get sued by Sarah Palin for millions of dollars. I'll let you know what happens.
Anyone who can read, click and type can become an author or a publisher. That's sad.
Update: I'm having so much fun that I upgraded my freebie website to a paid one so I could have a normal URL: 99BuckBooks.com. I'll probably put links to some of my books on it so I can sell some books to cover the cost of the website.
. . . . .
NO, I'm not really starting a self-publishing company. This was just an experiment to see exactly how low the "barrier to entry" is in self-publishing. I'm too busy with my own books to publish the work of other writers. I learned that it's very easy to form a self-publishing company. Before you choose one, carefully investigate its qualifications and successes -- and remember: price isn't everything.