Hi Robert,
Welcome aboard!

Thanks for asking the questions that you have!
There are two places that have been created specifically for small press publishers and authors to promote their work.
Log in to the main site
here. After having done so, be sure to add your book to the "Marketplace". It allows you to upload a cover pic, a _link_ to your publisher (fatcat) and as much promo-text as you would like. Any book you upload to the
Marketplace will automatically appear in your profile,
here.
You are also welcome to announce your
new release here. It might also be appropriate to give a heads up to our moderator
scififan. He moderates the
science fiction forum. He could also set up a user-submitted review of your book if you like.
As you have already, join the forums and start sharing your opinions and perspective. Often, there will be discussions about the direction the Small Press Exchange has to take, and decisions will be made as to the functioning, structure of this site. Share your knowledge, and contribute to the community by taking active part in discussions, and providing feedback.
As this site is, at its heart, a social network, the more you contribute, the more you will take away. The more insight you provide, the more advice you give, and the more you help out, the greater impact you will have on the site.
For a year or more, a common buzzword uttered by people out on the web has been "social media"—the idea that one-to-many communication on the Web has given way to many-to-many communication, and that traffic and conversation naturally cluster around content, such as videos, photos, blog posts, and bookmarks. Examples of social media in action at the Small Press Exchange include our
bookmark directory, where users can save, share, and tag Web pages they've visited;
our profiles, which act as a social networking service, allowing photo uploads, etc. Our
reviews section, etc. So feel free to submit interesting sites to our directory, or offer to write a review.
So it's a party here, and you at most parties people will sometimes promote themselves. On this website, it's a matter of determining when someone steps over the line, and there's no absolute rule. Same as in real parties.
If you need a hand with any of the site's features, just give me a shout!