Forms / structured data feature in Plone 4

Question

We are trying to make a document-managemnet / knowledge management portal using Plone 4. We would like a forms / structured data feature in our webapp with posibility of defining forms through the web, having workflows using these forms and being able to create reports from them (preferably in some format that facilitates simple and nice looking or skinnable printouts).

Any pointers to modules, documentation and/or literature would be great. Thanks.