Re: I have created a blog and only have the Blog Nav on left

"there must be a setting."

You would think so, but apparently not.  What you can do is open the underlying posts page (post.aspx)  and add the quick launch code (via Sharepoint Designer) or add a list web part to the left nav. in the browser.

To open the posts page, append this to your blog url:

/Lists/Posts/Post.aspx?ToolPaneView=2&PageView=shared

An unstyled web part would look like this:

http://wb2-web.sharepoint.com/publicblog/default.aspx