1)
Write a great book, preferably the first in a
series. Get at least one other person to read it and tell you either it's great or what's wrong so you can fix it. Preferably get five or six
beta readers to do this. Get someone whose grammar and punctuation skills are good to
proofread it. Fix the errors.
2)
Format the book correctly. I recommend the Smashwords Style Guide, but look up formatting threads on KBoards and you will get 100 different opinions. Just get it formatted correctly.
3) Write a
book description that makes potential readers want to read the book. Do not write a summary of the book. Write a teaser that gets them interested.
4) Figure out which
genre your book is.
5) Figure out which
keywords a reader interested in books such as yours would likely enter in a search engine. Look up Amazon categories in your book's genre to find out which keywords you need to enter in order to get in the sub-categories that will best showcase your book.
6) Get a
book cover that tells potential readers which genre your book is and what the mood of the book is, and makes the book intriguing. Get this professionally done ($50 - $500) or buy a professional's pre-made cover ($25-$100).
7) Set up a
website that houses a way for readers to sign up for your
mailing list. This can be a free blog that readers subscribe to or a fancy pro website with a fancy mailing list. Look up mailing list here on KBoards for 100 different ways to do this.

Put
back matter in your book(s) that includes a link to your mailing list sign-up and encourages readers to sign up for new book release alerts. You can also include Facebook, Twitter, your email address, your Goodreads profile, and any other way readers can communicate with you. But for sure have a mailing list sign-up link in the back matter of your book.
9) Now get it
proofread and formatted. Sorry, jumped the gun on that earlier.
10)
Publish to Kindle Direct Publishing, Kobo Writing Life, iTunes, Google Play (but read tk's Google Play thread before you publish there), and Smashwords to distribute to Nook Press so you can go permafree there. You can publish at a price other than permafree to see if your cover etc will float you. If it sells, great!
10)a If your book does not sell right out the gate (and most books do not), I would make it free right away in order to start getting people on your mailing list. If this is you, then as soon as your book is permafree, hit up some of the free sites in step 14, one each day maybe, while you complete steps 11-13. Look up how to go permafree here on KBoards if you need to.
11) Get
at least 25 good reviews on your first book. If your reviews are not good, then repeat step 1. The more the better. Once you start advertising, you will get drive-by one-star reviews and they really hurt your review average unless you have at least 25 good reviews. This varies by genre. In thrillers and romance you should probably have 50. There are many threads on KBoards on how to do this. You can do this and step 12 at the same time, but they both must be done before you lay out any money in step 14, for best results.
12)
Repeat steps 1-11 with at least one sequel before you advertise. This is so that your readers have something to move on to once they finish reading your one book. All the rest of this is marketing, too. It may not seem like it is, but it is. That is what I have learned in my two years here on KBoards. Marketing is everything you do to get your book into the hands of readers.
Tell your mailing list each time you publish a sequel.
13) Make the first book free if you haven't already. Or plan on 99 cent sales. Free works much better.
14) Advertise. The best places to do this vary. Bookbub is king right now, followed by Kindle Books and Tips, Booksends, Freebooksy, Ereader News Today, and Pixel of Ink. Advertising sites wax and wane, though. Keep your eye on this board to keep on top of which sites are doing well. Here is a list of 100 sites to try.
http://www.andrew-butcher.com/100-websites-for-kdp-select-free-days---submit-your-ebook.html