Here is a helpful list of suggestions if you wish to publish your book:
1. Write, obviously!
2. Read multiple books similar the one you are writing. It will give you a good idea of what is out there and help you develop a critical eye for your own work.
3. Have your work read by others not related to you or your best friend.
4. Join a critique group. There are numerous ones out there, just do a Google search for critique groups in your area or online critique groups. Meetup.com has a number of them, as well (not a sponsor, just like it as a resource!).
5. Build your platform. Start developing a readership online through your website and/or blog. If you aren't on at least two social media sites promoting yourself as a writer, then you will be left behind. Publishers will look at how you currently promote yourself and share your work to see if you would be viable as a potential author for them. Remember, they're spending money on you, so they want to make sure their bottom line- sales- will be met. Having a following will provide backup proof that you can make them money.
6. Beta Readers- for your finished book or to read chapter by chapter. People who will read with a critical eye, making sure that you are staying on topic with your story.
7. Professional Editing- This is an absolute must, even if it is just for copy editing to ensure that your punctuation, grammar, spelling, style and structure are error free. A copy editor will charge either by the word ($0.014 average) or by the page ($3-4.50 average), but it will be by all words or pages, not just those they corrected!
8. Research! Find out what agents or publishers work with and go from there. If they work with authors who write what you write, more than likely, they will be more interested in working with you. Most publishers have a submissions guidelines page on their websites. If they do not accept unsolicited materials (Sleeping Panther Press does not), then do not submit anything to them.