I Recommend either a. Scanning some pages in and make a pdf sample (16 or so pages) b. Giving out free copys of the book as long as people write a review.
Consider a promo blog? Maybe post a chapter on there? or samples of a few chapters? and a synopsis etc
selling in ebay or amazon? or you can make a website and post some of the contents on social bookmark sites.
Sell it through Google Adwords. Start an affiliate program. Rank on the search engines and sell it through your site
Establishing a blog and selling on there is also a technique i've seen used well. Ebay and Amazon are great ideas.
1) Clickbank 2) Joint Ventures - find others promoting books similar to yours with large email lists and offer them a good commission, this will definitely get you some quick sales.