Once you've established a blog, be sure to submit a Technorati Profile and submit your blog using SocialPoster These tools will signify the search engines that your blog is out there and to being spidering the site on a regular basis. In blogging, when search engines spider your site, its called a PING. With each ping, your content gets indexed.
Over time your blog will gain a favorable Google PR and you can use that to attract external links and transfer the google PR to your main website. Learn more about Blogging at MarketingScoop.com