"valid" RDF in XML files

Hi,

My boss asked me to have a look on RDF to do the following : 

We have a lot of RDF files, describing software features, and validated by a
schema.
We would like to add RDF/XML metadata to those files, but as there is a LOT of
files, we would like to include the RDF data within the XML files.

I managed to do that by adding the following line to the Schema : 

<xsd:any namespace="http://www.w3.org/1999/02/22-rdf-syntax-ns#" 
    minOccurs="0" maxOccurs="1"  
    processContents="skip"/>

which allows me to add a <rdf:RDF ....>....</rdf:RDF> tag in my XML file, at the
location specified in the schema. An RDF parser finds the RDF information, and
the XML validates correctly, I'm quite happy.

My questions are : 

- 1 : is this the good way to do such things?? Or do I need much more
explanations about RDF and the way to use it?

- 2 : If I want the included RDF information to be checked against a model, how
should I proceed? Do I need RDF Schema???

Thanks a lot for your answers.

Etienne Lacazedieu