Hi Josh Anderson,
Most of the RadControls have two CSS files associated with them, a base (containing common properties, most of which required for the proper functionality of the control) and a skin (Default, Vista, etc). You can disable the first one (which is the one that you describe) through the EnableEmbeddedBaseStylesheet
the Telerik team
Check out Telerik Trainer
, the state of the art learning tool for Telerik products.