Are you talking about the resource files you have added to your form in InfoPath? In this case, those files are available to be used by your code - they reside the in the same folder your assembly is being executed from.
That means that if you have a file called "data.txt", you could read its contents in this way:
string data = System.IO.File.ReadAllText("data.txt");
Note that your form has to be fully trusted which is always the case anyway for solutions with business logic that run in MOSS.
Still, if your data is in the XML format, there is an easier way to access it. Instead of adding your XML file as a resource, add it as a data connection (and then tell InfoPath to add the file as a resource automatically). You can then access those values by either dragging them into your form or by using rules - so no need to write code.
I hope this answers the question...
David Airapetyan / Software Services ArchitectQdabra® Software / Streamline data gathering to turn process into knowledge