After logging into your CPanel:
- Click on the "MySQL" icon
- Enter your database name into the "Db" field and click "Add Db"
- Create a new user by inputting the username and the password into the fields provided and then clicking the "Add User" button.
- From the drop down lists, choose the user and the database you have just created.
- Click the "Add User to Db" button
You can easily manage your databases by going to 'phpMyAdmin'. It's also located under the 'MySQL Databases' icon in your control panel.