As you prepare for your book to come out, a great thing you can do in advance is to get together a press release, and there are a few sites that will send them out for you for FREE.
The only downside I had with the ones I have sent out is that I wanted to put my contact info as misspoirotatymail.com instead of using the @ sign. Why does this matter? Once that release goes out a bunch of spammers will flood your inbox with a bunch of stuff you don't want or need. Fortunately, they are well known spammers and 99% of it deleted itself when it arrived in my inbox, so that was nice. So, it's kind of a give and take. You could set up a separate email I suppose for things like this, it just depends on how much it bothers you.
Here are the sites I have come across where you can submit a press release for zero dollars:
And here are two others, but please note - they are NOT free:
You can also post at Digg and that's free, and you can say the same type of thing as your PR, but you need to have a link to it, so the way I work around that is that I put the PR in my blog and then link to the blog page.
For those of you who have never put out a press release, don't fret, it's not that hard, and yes-you can do it yourself.
Some advice and examples can be found on these sites:
Haunted Computer Books
And finally, here's my latest press release.