It's not just a cliche. Books need a beginning, middle and an end.
In fiction, a story needs to go somewhere. A reader needs to care. If you want to be published, you need to write for the reader. (If you want to write for yourself, great, but go buy a journal!) A good story needs a strong narrative arc, character development and identifiable themes.
For non-fiction, readers need to learn something, not get confused by a sea or words or jargon. Are you presenting an argument or thesis? Communicating with a reader who doesn't know what you know is the key.
Do you want to tell the world your story? Real life is confusing, and if it's going to be a book, you are going to have to assert some order. (Much easier in a book than in reality!)
(a) Write in sentences. (b) Check your spelling. (c) Be consistent. (d) Punctuation is your friend, not your foe.
(e) All of the above .
Pitch to a publisher
A publisher needs to know what your book is about, and won't have the time or inclination to read it without some convincing. You need a proposal, a synopsis, more than a few reasons why is your book worth publishing and a nice long list of who is likely to buy it. Can you write a compelling chapter or 25? You'll need to prove it.
Genres I have known and loved (and edited)
Biography, business, children's books, literary and popular fiction, health, history, management, memoir, law, politics, narrative non-fiction, reference, self-help.