Hi Karyn,
Assuming you have a website, the first step is to optimize it so that it ranks well in the major search engines. Do you know what you would most like it to rank well for (a specific keyword phrase)?
In fact, if you want to post a link to your site, maybe we could take a look at it together and work on it from there.
Next, I would recommend:
2) Test/Tweak your sales copy
You may want to get some "reviews" on your copy, layout & cover graphic before "going live".
3) Set up a Pay-Per-Click campaign
(on Adwords, for example) to find out how well your site converts visitors into buyers - And which keywords work best for your site.
4) Set up an Affiliate Program
so that others can/will promote your ebook for you. Once you have this in place you can contact webmasters and list owners that already reach your target market... and allow them to review your book so that they can personally recommend it.
5) Write articles related to your topic
These can be submitted to article banks, article databases, webmasters & list-owners with related content, and can even be used by affiliates to pre-sell your book. Be sure you include a compelling signature that takes readers to the sales copy for your book.
I'll stop there, and we can work on any of this together if you like!