1. Tweet about it.
2. Make a book trailer.
3. Ask your readers to send in images of them with your book and then pin them on Pinterest. (people love the human connection)
4. Comment on threads in Facebook groups or on other people's threads to build your reputation as an expert.
5. Write a press release for PRWeb. It's a great way to get some backlinks to your site and maybe even some press interest.
6. Do a presentation at a local meetup group. Don't 'sell', just give great information, and make sure to have some books to hand in case people ask.
K.I.S.S. method, keep it simple silly! You can do it! Start today,