Take a look at the following tutorial:
http://code.daypilot.org/17910/html5-event-calendar-open-source
It uses the Lite version to show how to load data and handle events using a very light-weight server-side part. It uses simple jQuery $.post() calls to submit changes. The data is loaded in JSON format. This makes the server-side part very thin.
It includes examples for PHP and ASP.NET MVC but you can easily implement the server-side part in ASP.NET WebForms. Just you will be returning JSON responses.