Well, published authors are not superior to unpublished stories but an editor will look at the writing of a published author, and if he sees nonsense, he will give it a chance will keep reading the book to see if it makes any sense. If the same thing happens with an unpublished author, the editor will toss it out immediately. If you will write a textbook, things are different and you almost certainly need to be a recognized researcher in your field. I have more on writing a textbook at
and you can apply, at least some of the principles set out there to your book, whatever format it is going to be in.
If you would like to publish with a traditional publisher, a lot of times you need an invitation for them to spend money evaluating your book, unless its a new publisher company. They don't really like getting cold proposals, so I suggest you start small, with a relatively new company and work your way up up, unless you can get a good offer from an established company.