As you are new to our Chart control, I would suggest you to try our new ChartView control. Using below link you can find more information on how to create a pie chart:
Info on how to create chart in a data bound scenario can be found here:
I have also attached a sample project demonstrating the above.
In case you want to use the old chart control, you can find a lot of useful information here:
Hope this helps you get started.
the Telerik team