Everyone says content is king. Without a doubt, a static website draws no one's interest and pushing stale, unfocused, content is not much better. Once the decision has been made to blog, keeping the reader's interest with well written articles will keep them coming back.
The number one most effective SEO technique is creating great content mixed with serious determination. A single blog will hardly draw a yawn, but hundreds, even thousands of articles, will increase the chances of being found dramatically. Every other tip will depend on this.
Pick a great platform. Hardly anyone uses plain old HTML pages to publish. Content management systems rule the roost. A CMS, like Wordpress, is very popular for a reason. They provide great software to make posting easy and are supported by great communities who continually enhance the system through plug-ins and themes.
Site design is critical. While it is certainly nice to have a page people like to look at, there is a bigger issue. Poorly generated HTML can stop a search engine web crawler in its tracks. The blog might look great to the reader, but Google might have no idea there is even a page past the home page. There are great themes out there, both paid and commercial, just waiting to be used.
Use a sitemap. One of the best reasons for using a CMS is having a plug-in that can do this automatically. Submit the site map to Yahoo. Yahoo requires signing up for their network, but there is no cost for it but the time it takes. To submit a sitemap to Ask, simply type http://submissions.ask.com/ping?sitemap= path to sitemap in a browser.
Utilize search engine friendly URLs, tags and keywords. Another great reason to take advantage of a CMS. Blog titles can automatically be generated while tags will be used to create keywords on the page.
Get out there. Write on other sites like Technorati, Helium, or as a guest on someone else's blog. The exposure on another site can trickle back and often lets a great article have a greater exposure than it might otherwise have when first starting out.
Use Google Alerts. Google will email new search results on topics of interest. Very useful for keeping up to date on the latest news in a niche. It is also useful for finding relevant places to make comments and posting links back to blogs with similar content and a great way to channel users to a site.