Just as your would work to optimize static webpages for the search engines, you also need to make sure that your blog entries are also search engine friendly. Blogs are traditionally easy to get indexed in the major search engines in a relatively short amount of time, but when you use SEO techniques, that indexing happens in a much shorter time, and you will find that you get better rankings.
The first step to SEO for blogs is to use your primary keyword in the domain name. It is always a good idea to purchase your own domain name, even if our blog will be hosted by a blogging service. Most blogging services allow this, but may charge a nominal fee for your usage of the service. Also make sure that you always use your primary keywords or key phrases in the header tags of the blog, as will as in the titles of your blog entries. Use the H1 and H2 tags for blog entry titles.
Use both primary and secondary keywords in the body of your entries. This will help you get listed for those additional secondary keywords in the search engines, but use care here. You dont want to overdo it with the keywords. One primary keyword or key phrase and one or two secondary keywords is enough for each blog entry. Make sure that your keywords are used in a natural way, meaning that your sentences make perfect grammatical sense and your paragraphs flow in such a way as to not make it obvious that you are targeting keywords.
When using links in your blog entries, make sure that the anchor text includes your primary or secondary keywords. Search engines are especially partial to these types of links, especially if you are linking to quality sites. Also use the alt tags for any photographs that you use in your entries. Just be very careful not to use keyword stuffing techniques, as the search engines will penalize you for this.
Leaving comments on other peoples blogs is a part of search engine optimization. Using Trackbacks, and having other blogs track back to you is also a part of SEO, and it is very important. You want as many incoming links to your blog as possible. Also make sure that links to your archived entries are on every page of your blog, even if those archives are done by month. This allows the search engines to find and index them more easily.
Manually submit your blog to the search engines and directories, as well as to blog search engines and directories. Also ping the blog search engines after each entry that you make. This will help the regular search engines to find those entries more quickly.
Make sure that you update your blog on a regular basis, adding new search engine optimized content at least once a week, and preferably several times a week if not daily. Avoid moving your blog around. Decide where you are going to start your blog, and stay put. Ideally, you should have your own domain name for your blog.