[Zope] How to write a product.

Hi. I want to write a product, like the calendar in MSOutlook. People should be able to add private and public events. Since I have never written a product before, what could be used as a good reference? Seems to me that one should use zclasses, with some logic in python. I had a look at ZDiscussion yesterday, is it doing things the "right" way? /Magnus