How to use a datatable as datasource for ReportViewer?

I'm fairly new to ReportViewer. My report is a bit odd and the only way I can get my head around it is to dynamically create a datatable as I'd like the data to be presented in a ReportViewer Table.

How do I get this freshly created datatable to be the datasource for the ReportViewer?

This is pretty urgent cos I have everything else working.

Thanks,

Geoff