I was going over the developer help of SOAP Service rules. In the 'More' section there is reference to a PDF document 'Building SOAP Services'. It is mentioned that this document is present in the 'Integration section of the PDN' area. Similarly there is another document called 'Testing Services and Connectors'. I have seen references to other such documents elsewhere as well.
Sorry you are having difficulty finding documents. The best way of viewing information grouped by topics is by clicking the Topic menu link on the home page of the PDN. Here, you will see and in your case click on the Integration link for information. Unfortunately we do not have a single page where all PDF files are located.