Jeff Marks' book, INTENT TO SELL, was my constant companion for several months when my first book was contracted. I'm sure there are other good tools out there, but that one, subtitled "Marketing the Genre Novel" was a good starting point for me, minimizing my newbie mistakes as much as possible. The most valuable thing I learned, (and the news is everywhere but I just needed to absorb it) is that nobody cares about your book more than you do.
A few more people care about HER HIGHNESS' FIRST MURDER. Reviewers are saying nice things. Librarians I've never contacted before recognize my name. And people I meet often mention having visited my website or read about me in the newspaper, etc. The question is, does that somehow parlay into sales, the only thing your publisher wants to hear about?
The way to spur new book sales is, as far as I can tell, doing the same things I did when no one had ever heard of me: sending out postcards, bookmarks, and press kits. Making the rounds of libraries and bookstores everywhere I travel. Attending author/reader events. Blogging. Providing new material on the website. Interviewing. Guest blogging. Promoting.
Oh, and by the way, I really need to finish that sequel.