The main reason why wordpress CMS is preferred over the other available Blog scripts is because how close wordpress script interacts with the search engines. In addition they have excellent plugins that would make it more in sync with the search engine and hence with little efforts on SEO you could achieve great exposure. Below are few excellent SEO plugins for the year as of 2011.
All in One SEO Pack – The most popular SEO plugin that would sync up your blog with search engines. Including keying in the keywords, tags, title etc along with the posts.
Google XML Sitemaps – A very important plugin that Should be installed for sure on your blog as it automatically creates an XML sitemap and helps crawling your website more effectively by the SERP bots.
Automatic SEO Links – This plugin allows you to choose a word or keyword for automatic linking, both internal and external, set many options like – set anchor text, choose if it should be “no-follow” or not, and more.
Meta Robots WordPress plugin – A solution to add robot metadata to any page of your choice on your blog. You could also add no-follow attributes and chose to index or not index pages as to avoid search engine taking it as a duplicate accounts.
SEO for Paged Comments – This is an excellent plugin for a reason – with the addition of the paged comments in wordpress from 2.7 version – there was a potential problem with search engines thinking having an impression that your blog had duplicate content as the post would appear on each page.
SEO Friendly Images – Images can be a great source of traffic as well. This plugin would help you add proper tags to your images.
SEO No Duplicate WordPress Plugin – If your website or blog has duplicate content as for any reason then this plugin allows you to instruct search engines – which content to instruct and which not to instruct.
SEO Post Link – Long canonical URLs would not be search engine friendly and this plugin would automatically populate shorter search engine friendly links for easy and smart indexing.
SEO Title Tag – A simple but excellent plugin that allows you to add tags to pages of your blogs as well.
Take Home: This is an excellent list that you should certainly try on your blog and that would help you get more exposure on your blog