Google Blog Search allows anyone to search blogs and only blogs. Just as you would want your site to be listed in Google search you also want to be listed in Google blog search.
The quick and easy way to assure you are indexed in the Google blog search is to manually enter your sites URL, what they call a ping by going here and simply pasting your sites feed address. A feed address may appear as “yourblog.blogspot.com/atom.xml”, “yoursite.com/wp-rss.php” or “feeds.feedburner.com/yourfeedname”. Enter your feed and submit. While this is easy it would be ideal to alert Google and others automatically every time your feed is updated.
WordPress and others have this set up already, recent versions of WordPress already have the Google blog search set to be pinged. However if you are using an older version of WordPress and do not wish to upgrade or have another content management system that has an XML-RPC client then check to make sure it is set up. In WordPress you navigate to the settings –> writing or in older versions options –> writing, there you will find the Update Services section, check to see if this is listed http://blogsearch.google.com/ping/RPC2 and if so you are fine otherwise paste it in and save changes. If however you have a rest client the URL is http://blogsearch.google.com/ping.