Technorati is a popular web directory service that indexes blogs, ranks them according to popularity, allows people to create bookmarked blog lists and allows people to do a search based on categories, called Technorati tags. If you use tags in your blog and ping Technorati when you write new entries, you will likely see an increase in your blog traffic and your ranking.
Join Technorati via its website by registering and claiming your blog. The act of claiming the blog creates a link from your user name to Technorati. The blog claim process is very simple and offered via a variety of easy-to-follow directions that might depend on the blog platform that you are using. Kodus to E-How.com
Write Technorati tags into your blog. Do this by either adding relevant text words that relate to your blog or that categorize your blog or by integrating tag links into your text. Some people add a section at the end of the blog called tags and simply list several links. Others integrate tags into their blogs, which can look more streamlined and result in a cleaner looking blog entry.
Choose popular and relevant tags to bring visitors to your blog. You can check a tag's popularity on the Technorati home page to see what today's popular tags as well as today's popular searches. Either click on them to see blogs categorized in that category or write your own blog with a tag listed in order to later find your blog entry under the directory for that specific tag.
Ping your blog when you finish writing a new entry with tags. Your homepage at Technorati has a tool that will allow a ping, which means that it will notify the directory that you have a new blog entry. It will classify your blog under your associated tags and notify those who have "Favorited" you via that user's homepage.