Hi,
I would recommend to install/import the sample Corporate site template - for example into a testing instance of Kentico you have (this way you will not overwrite any of the existing global objects in your current instance).
Then, in the Community section is an example of the blog pages. The templates used there are the portal engine model, but the idea is the same.
The thing is that you need a listing web part that will list all the blogs and then a web part that will list the blog posts under certain blog. So, the idea is basically the same as when listing news. The only special thing about blogs is that there are used special page types and the logic to automatically create blog month "categories" is there.
Also, the documentation assumes that you have the sample site template there - so you have the page templates available for selection. If you have started for example with blank site, you will need to create and configure the page templates for blogs from scratch as well. Here is a brief description of the structure and template and web parts (.
/Blog page (page template A, with a repeater1 which will list all the blogs underneath this page)
----John's blog (page template B with repeater2 which will be listing the blog posts)
--------blog posts (inherits page template B)
----Mike's blog (page template B with repeater2 which will be listing the blog posts)
--------blog posts (inherits page template B)