Here’s an interesting article that lists several things to do after starting a new WordPress blog. Things-to-do-after-starting-a-new-wordpress-blog/
The best tip on this page, and the one that I’ve just completed, is an installation of the plug-in to generate XML sitemaps for WordPress. It’s amazing how easy this was to install! In about 3 minutes I was up and running with a new sitemap. The coolest feature is the auto-submit feature to Google and other search engines, notifying them of new posts to your blog. Perfect for SEO!
Google has their blog search tool (currently in beta) as well as a pinging tool that checks thousands of blogs daily. They encourage you to use a tool such as this plug-in to update their blogsearch service with new content.
And while we’re on the subject of plug-ins for WordPress, it’s impressive just how many there are. Take a look at the official site.