Couple of weeks before, I have written an introduction about the chart control available in .Net framework. In that article, I explained the basic usage of the chart control with a simple example. You can read that article from the url http://weblogs.asp.net/sreejukg/archive/2010/12/31/getting-started-with-chart-control-in-asp-net-4-0.aspx.
Documentation is an essential part of any IT project, especially when you are creating reusable components that will be used by other developers (such as class libraries). Without documentation re-using a class library is almost impossible. Just think of coding .net applications without MSDN documentation (Ooops I can’t think of it).