The following web hosting control panels are available for pre-installation with your Dedicated Server. These control panels give you an easy to use web based interface to add uses/websites/databases/emails/ftp etc..
DirectAdmin Control Panel

DirectAdmin is the easiest to use control panel. There is no limit to the amount of domains or user accounts that can be hosted with DirectAdmin. DirectAdmin avoids downtime by automatically recovering from service failures. DirectAdmin has a large active community forum to help with any questions or problems, if any.
cPanel Control Panel

cPanel and WebHost Manager (WHM) combine to form a fully featured web hosting control panel system. The cPanel and WHM package allows you to manage every aspect of your server's web hosting needs through two easy to use interfaces. cPanel and WHM are both installed with every copy of the cPanel and WHM software and must be used together.
Plesk 10 Control Panel

Plesk 8 is available for both Linux and Windows 2003 platforms. Plesk is a comprehensive control panel solution used by leading hosting providers worldwide for shared, virtual and dedicated hosting. The control panel is designed to simplify the management and administration of web sites. Plesk control panel automates a large number of tasks that allow service providers to reduce operating costs and resources while at the same time increasing profitability, efficiency and customer satisfaction.