These are important and in some ways helps you better understand SEO and help you fight SPAM
- All In One SEO Pack=Out-of-the-box SEO for your WordPress blog
- Akismet= Spam butt kicker!
- Google XML Sitemaps
This plugin will generate a special XML sitemap which will help search engines like Google, Yahoo, Bing and Ask.com to better index your blog. - Google Analytics for WordPress =
This plugin makes it simple to add Google Analytics to your WordPress blog, adding lots of features, eg. custom variables and automatic clickout and download tracking. - Wufoo Shortcode Plugin
Enables shortcode to embed Wufoo forms.