You can use the ReadOnly
property of the RadScheduler to allow/ forbid the rights to insert/update/delete appointments.
You can use the ASP.NET Web Site Administration Tool to create and manage user accounts. After that you can add each user as a resource to the RadScheduler and show only the appointments per user. Please take a look at this demo for a sample.
Please let me know if you still have any questions.
the Telerik team