1. Set up a blog
These days you can start a blog for free with WordPress.com.
Commit some time each day to write posts on your blog. People who find your blog can interact with you and others through your blog comments system and you can quickly build a following this way.
Alternatively you can start a blog on a domain name (your name or a book name of yours) and host it on a web hosting service like Godaddy, Bluehost or any reliable hosting service. This option is preferable as you own the domain and site, and are not just using somebody else’s platform, as you would if you used WordPress.com
2. Link from your website to your books
As you gather a following on your blog your followers will soon become familiar with your writing style and voice, and will naturally want to find out more about you. Displaying your book cover image in the sidebar of your blog or at the bottom of blog posts will give people the opportunity to click through to Amazon to find out more about your book.
While many people dismiss Twitter it is a great place to find like-minded authors and fans. You can search by subject within Twitter and connect with people interested in your topic of choice. Making connections this way is a fantastic free way of spreading the word about your book.
4. Book shop readings
Many local book shops are struggling in todays economy, so are always on the look out for ways to attract new customers. How about approcahing them and asking them to allow you to read your book aloud to the customers. Book store owners like this as it brings in customers and attracts the attention of journalists and newspaper writers and is a great way to get publicity.
5. Gather a list of customers
Add a simple email form to your blog. With this visitors can enter their email to get on your newsletter. Then when it comes time for you to launch a new book you can simply email your email list to ask them to critique, buy or read your book.
I hope these few suggestions help.