Even before you publish you should create a marketing strategy for your forthcoming books.
SOCIAL MEDIA FOR WRITERS
By making connections, you will be building your audience and selling books. You want to create the best version of yourself online with LinkedIn, Facebook, Twitter, Pinterest, Goodreads, Google+, Tumblr, Instagram, a blog, and other social media sites.
Many literary agents not only want great writers, but they also want a solid social media presence.
An excellent book to buy about Social Media is SOCIAL MEDIA FOR WRITERS by Tee Morris and Pip Ballantine.
Here's the link for Social Media Just For Writers: http://www.amazon.com/Social-Media-Just-Writers-Marketing/dp/1480030821