newbee with pentaho: looking for forecasting tools

Hi,
I'm lookifor forecasting tools, and pentaho has one.
I found it in the intaview application, there is the forecast tab.

but no dcumentation or sample available!!!
how to use this tool?
I want to connect it to an existing database or a CSV file. nothing complicated... but apparently this simple step is allready too complex!

any guide? video?
thanks.