Check this:
XmlDocument doc = new XmlDocument();
doc.Load(ofd.Filename);
Now use XmlNode to traverse through nodes:
XmlNode rootNode = doc.SelectSingleNode("Dados");
Retrieve other nodes as well in this manner:
XmlNode nomeNode = rootNode.SelectSingleNode("Nome");
XmlNode saxoNode = rootNode.SelectSingleNode("Saxo");
This should give you a start.