It is rarely required to handle RadRibbonBar events. Most of the time you need to handle the events for the elements contained in RibbonBar e.g. you may want to handle the click event for a button placed in some of your RadRibbonBar groups.
Adding event handler for some of those elements is no different than the situation when the controls are used independently. You can add events either at design time using the Properties grid in Visual Studio or you can subscribe for events programmatically.