What's in a Name?
Since your name isn't Stephen King or J.K. Rowling, you need to make a name for yourself. Branding is just as important to an author as it is for consumer products. What is your name? Are you going with a pen name, your own name, or an initialized version? I went with initials because I want more focus on my stories than my gender or my own story. Once you've decided on your author name, stick to it. Amazon isn't very flexible when it comes to changing names, and your book reviews won't switch over if you change it during the midway point (I know from experience).
Audience Targeting
Who are you selling your story to? Is there a specific demographic, gender, or interest group? For the younger generation, it is difficult to gain the interest because you've got to get into places that young people will see your stuff. I would suggest going to an event, such as Comic-Con or a gaming expo or something in that realm. There are many book expos that you can sign up for as well.
Social Media
The easiest, and cheapest, form of marketing is to gain an audience through social media outlets. That includes Goodreads, Twitter, Facebook, Instagram, Pinterest, Reddit, Youtube, Bookbub, and others. I suggest getting these going before you ever write a single word of your book. Wattpad is also a good tool in gaining feedback on your writing. Interact with readers, authors, and others in the industry so that you can tweak your writing/story so that it will be perfect when you finally decide to release it. Plus, gaining early interest and reviews will help to get your name out there.
Giveaways
Goodreads and Amazon are a great way to get your book out there for readers. I always do a Goodreads giveaway for at least one paperback copy of my books. This will help add your book to reader's lists of books, and Goodreads will constantly send mailings to those readers about your giveaways. Amazon is great for adding twitter followers or tweeting your messages to that social media outlet. It will also send your ebook to potential reviewers.
Reviews
This is one of the most important tasks you'll undertake as an author. To gain reviews for your books is crucial in gaining exposure. Amazon, and many other book blogs, will look at your reviews to assess potential for further marketing of your books. You've got to get at least 50 reviews for Amazon or Bookbub to place your novel in their marketing emails. 200 reviews with an average of 3.75 stars out of 5 is worth more than 20 reviews at an average of 4.5 stars. To start, I would suggest asking friends and family to read and review, then you've got to get readers to place that review. That is the difficult part. Bug them. It is worth it.
Newsletter
The mailing list is essential. Its a bit daunting to get up and running. I suggest starting with Mailchimp since its free for a certain number of emails, then switch over to another mailing service. I would also suggest getting your website to pop-up a window that collects emails that you can utilize in reaching out to your fans. I would start by doing a newsletter every few months, and then every month. Include your updates, new giveaways, book releases, etc.
Advertising
There are many websites out there that you can pay to advertise on, but they are not very effective. I know, I've tried. Paid way to much, and didn't receive that much in return. The best course, if you are paying, is to use the Amazon Marketing Services (www.ams.amazon.com). I use keywords that relate to my novel, along with a few other authors or books in my genre. This will post your book in the display for sponsored products, and is the best way for readers to find your book. Facebook advertising is also good, but its way too expensive.