I think you can learn quite a bit from Tim Ferris (the author of the 4-hour work week). He started marketing his book way before it came out by way of:

1. A website that complimented his book

2. A blog that talk about things related to the book

3. He reached out to bloggers and built a relationship (http://text.co.uk/internet-marketing-news/how-to-market-to-b...)

4. Get interviewed. Podcasters are always looking to interview people with interesting stories and of course there are many book review sites and podcasts.

All these will build enough anticipation and hype that once your books hits the shelf you should have generated significant buzz.