How to add contents through block after enabling the blog module in drupal 7
Based on your comment above, you want to display blog entries in a block on your website.

I haven't used the Blog module in a long while (it's functionality can be duplicated easily without enabling it), but I think the easiest way for you to do this is to use Views.


Add a few blog entries
Create a new View that displays Content of type Blog Entry in a Block.
Views creates a new block, which you can place anywhere you'd like via the Block Admin page.


If you are unfamiliar with Views, you should watch or read some video tutorials. This one is recent and seems to be up your alley.