There are six WordPress plugins I recommend to get your Blog or WordPress website started.
Official Facebook Plugin – Make your website or Blog “deeply social”. You can learn more about the Facebook plugin here: http://developers.facebook.com/wordpress/
Inbound Writer – Content optimization without over optimizing a page is now possible through this unique plugin. The inbound Writer plugin is designed to perform content optimization and give you a score on how well your content is focused while you are creating content on the fly. It also gives you resources to pull additional content from resources and related keyword terms for your topic.
Yoast SEO – This is the most complete WordPress plugin for your SEO needs. It will analyze your snippet preview, titles and descriptions to help you craft better snippets for your pages and posts. It also has and XML sitemap generator as well as an RSS optimizer to help you get the most from your WordPress site.
Cool Author Box – Not only does this add information about the author to the bottom of the content of posts and pages it also adds link to other posts by the same author and a link to the authors website. This plugin also allows you to add the ?rel=author tag to all of your posts. Simply edit the User Profile area and where is says your website put a link back to your Google Plus Profile and add the ?rel=author to the end of the URL string.
GD Star Rating – Ever wonder how those stars appear in the Google snippets? This is the plugin that does it. GDStar Rating is taking advantage of the rich snippet Google has introduced.
MaxBlog Plus Ninja Links – Create short URLS with your own domain and track the links activity. Also replace keywords in your blog with links going where you want them to cleanly. If you need to change a link destination, no problem just change it once in the interface and it is populated throughout your blog or WordPress site.