Before being able to use the DB class, we need to modify a specific configuration file.
The config file is located in /fuel/app/config/development/db.php Change the following
return array( 'default' => array( 'connection' => array( 'dsn' => 'mysql:host=faure.cs.colostate.edu;dbname={ EID }', 'username' => '{ EID }', 'password' => '{CSU ID}', ), ), );
If you can successfully access the MySQL server with these credentials, Fuel shouldn't have an issue doing the same.
I duplicated my basic form example and it now uses my database rather than a data text file. Download it from here to follow along!