Target a specific release date
Create the feeling that something valuable is coming. Build your list of supporters and fans with your blog and social media like Facebook and Twitter.
Start awareness of the book as early as possible to build anticipation
Consider asking for ideas from your base about cover design or promotions. Run a contest. I would recommend setting up a dedicated blog for your book. Start to release free quality content. Great content will start to create buy-in. And remember the law of reciprocity … giving away value at no cost will come back to you later.