When you use Microsoft Word to post to a SharePoint
blog, you can create your blog post just as easily you would any other
document. You can quickly check your spelling, add hyperlinks, add
pictures and tables, format the text, and then upload your blog post to
your site, without ever leaving Word.
Note To post to a SharePoint blog, you must have permission to contribute to the Posts list on the blog site.
http://office.microsoft.com/en-us/sharepoint-foundation-help/video-use-word-2010-to-post-to-a-sharepoint-blog-VA101790488.aspx