To increase he SEO of your blog or website, you have to help the search engines actually browse through your website. That’s why sitemaps are great.
Unfortunately, doing this manually can be a pain and you just really don’t want to do that with a blog. Fortunately for WordPress, there is a plugin called: Google XML Sitemaps. When you edit or update a post, then your sitemap is automatically updated and the major search engines are notified that the sitemap was updated. This makes the crawler a lot more friendly to your site which also means that you would get a lot more fun stuff out of it (eg. traffic). And everyone likes traffic.