Okay... A schema file simply defines what the XML must conform to. Unfortunately, there is no magic "generate" function that will generate all the nodes required by your XSD. The good news is that an XSD is essentially the same as the dictionary of a database. It describes a set of tables and a set of attributes. I have never tried to use an XSD to generate XML before, but if I was to try, I would start by using an ADO.NET dataset object. Create a dataset object and then try using the ReadXMLSchema function. This should initialize the table objects in the dataset and you can then populate tables using standard ADO.NET methods. Then when you want to generate the XML just use WriteXml or GetXml functions.
Just google "dataset ReadXmlSchema" for examples