Many people want to blog on their site. This is easy to do since a blog comes standard within Drupal.
The blog can be a single or multi use blog. Anyone with the appropriate permissions can post a blog.
The blog is located at /blog on your site. This page shows every blog posting that is on your site, 10 per page.
Each user also has their own blog. If pathauto has been turned on for your site, each user's blog is located at /blogs/username
The blog is pretty simple. If you want it to have advanced features like a month-by-month archive, links to places like Reddit and Facebook, etc., additional modules will need to be installed and customizations made.
Adding a blog is as simple as clicking on the "create content" link in the Navigation Menu and click on "Blog entry."
Add you content and submit the page.
You've now added an item to your blog.