Read and re-read your manuscript constantly before attempting to send for publication. Check for punctuation, spelling, grammatical, formatting and word choice errors and correct as needed. As you pore over your book, think carefully (and from an outside perspective) about whether the book you've created is worth submitting. If yours is a work of fiction, determine if your story is compelling, innovative and will appeal to a wide audience. For nonfiction books, make certain that your content is factual, well-researched and timely. Have a trusted friend read the book and give you an honest opinion. Hire a professional copy editor to read your work and make corrections.
Research literary agencies and/or publishing houses. Many agents and publishers have a special area of focus, such as nonfiction, romance, textbooks or children's books. Look for organizations that feature writers similar to you or work that is in the same vein as yours. Submitting directly to the publisher cuts out the middle man and gets your work in the publisher's hands faster. However, keep in mind that many publishers will only accept submissions from a literary agent. An agent, however, will do all of the submitting for you and handle negotiations if you are offered a contract.
Send a selection of your work, along with a short and courteous cover letter, to potential literary agents or publishers. Each publisher and agency will have different preferences as to the size of your selection and may have specific formatting requirements. Some organizations will only accept query letters, which include a brief summary of the book and basic information on the author. If you would like your work back, you should include a self-addressed stamped envelope. You may also simply ask that your selection be recycled should they decide not to move forward. Never submit to an agency or publishing house that asks you to pay any application or reading fees.
Continue to edit and improve your work as you wait to hear back from publishers and/or literary agents. It may be weeks, months or even a year before your work reaches the top of a readers' pile of submissions. Trust that your work will be read and given consideration. If you do receive a rejection, know that you are not alone, improve your manuscript, try again or explore other options.
Consider publishing your book yourself. There are dozens of publishing houses that will print and bind your book for a fee. While this is not the ideal pathway to publication, some have found success going this route. Self publication is fine if you just want to see your work in print, but if you want to have lots of readers and make some money, be aware that you'll have to do a lot of work to market and sell the book yourself. Another option is to e-publish your book as a downloadable e-book for handheld devices and online reading. Some writers have also had success starting with a blog to make a name for themselves.