Mod blog is very similar to waka with the main difference being a focus on chronology rather than directory structure.
So for now look at the waka documentation.

We inherit upwards through the wiki heirarchy so the pages */ and */blog on the wiki are used to generate blog content. This allows site wide layout code to go into the root of the wiki and effect the entire site and blog specific tweaks to go into */blog in order to edit the blog wiki page you need to use the following.

*/?page=blog&cmd=edit where * is replaced with your site name. You cannot simply visit */blog to edit as that is a page controlled by the blog module rather than the wiki module.