By default you will see the URL of your wordpress blogs with category name after base URL
Obviously you wouldn’t like to have category in the URL.
To remove category appearing in URL there are various ways, if you are php expert then you can modify the rewrite rules and play with permalinks.
Here is the simplest solution
Install this plugin http://fortes.com/projects/wordpress/top-level-cats/
Follow the instructions in the readme
If it doesn’t work then save yourself from reading all the comments and do followings
Options -> Permalinks
Change the Custom structure: to followings
Click on update and enjoy 🙂