Here are some simple steps to add a new blog to your site:

1. In Guided Tour - Back-Office under the tab click the link at the bottom to create a New blog.
2. Fill out the form for creating a new blog.
3. Click Save.
4. Now the blog is created and administrators have permission to post to it. If you want other users to be able to post to the new blog, then edit the blog and go to the permissions sub tab to set the permissions as you need them.