Be careful not to neglect the form of your manuscript: it should not be written by hand but typed in the word processor. This is called a typewritten. Favor the A4 format, structure your book in chapters, paragraphs and spare the eyes of the editor by choosing an airy text, a font size of minimum 12 and a spacing of 1.5. To make a book you have the best options now.
The most common mistake is to send your manuscript to all existing publishers. It’s a waste of time for everyone. Select the editors to which you will send your manuscript according to several criteria:
Genre: target publishers who publish the genre in which you wrote. To send a collection of short stories to an editor who only publishes novels is meaningless.
The editorial line: check well on the publisher’s website what its editorial line is …