I will give you some documentation and videos, which will help you to create a menu by using RadControls.
Here you can find information about the controls. How to create and work with them.
You may take a look at this wеbsite and see demos, description and source code connected with the ASP.NET AJAX RadControl Menu.
Please review the attached code. Here
is a video of the process for using the control in Sitefinity
the Telerik team
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