A properly created weblog will do the following for your website: (a) add rich content; (b) add interactivity in the form of user ability to post comments; and (c) if properly set up, can automatically ping major search engines when new posts are made. This results in more frequent spidering of your website by the major search engines, with the fresh content being picked up quickly and increasing your site's ranking.
But to really see an impact, more is needed. First of all, be sure to set up your weblog with an XML site feed, allowing for the easy syndication of your blog's content to third party websites - which in turn generates numerous inbound links to your website, all them relevant to your site's content, which vastly improves your link popularity.
Then, if you want to make a real splash, submit your articles manually to article submission sites - respected ones - which are easy to find by doing a simple search on the net. Finally, be sure to use your keyphrases, as in this case, search engine optimization, in your article. Update as frequently as possible, and submit to the article submission sites, and don't forget to ping the RSS feed directories.
A number of RSS feed directories are available - visit geckotribe for a start, and keep searching. You will find places (like this one, for example) which will post your article for free. People are starving for content. So feed them!
Matthew Foster is the President and CEO of ArteWorks Business Class - http://www.arteworks.biz - and has been active in the seo industry since 1995. Mr. Foster regularly optimizes websites for search engines, which appear in the top 10 results within 8-30 days. For more information, please visit ArteWorks.