Have you done any keyword research to target a certain audience? You can do all the book marketing and other crap till you are blue in the face, but if you don't know your audience it won't do any good.

Once you know who "your people" are then get yourself out there as much as you can. You want to position yourself as an expert in your area. Create Squidoo lens, write articles, blog of course.... put up pages and sites everywhere you can (and book mark them all).

Back in my graffiti days we called it "getting up" and putting our name everywhere we could... it's a lot like that in marketing.