The reason you don't have the answer you want is because you haven't yet asked the right question.
Answering your second question first (the easy one):
Assuming you mean the style guide of the American Psychological Association (APA), there is a link on the Wikipedia page to the APA style website. This is the only official online APA style guide, i.e. the one that comes directly from the American Psychological Association.
Their quick guide on references should give you most of the information you want, and you can search on the site for other specifics.
Now for the unasked question behind your first question:
Your question boils down to: "What is the citingcitation format for a PDF?" This is the wrong question. It is the same as asking "What is the citingcitation format for an envelope?" It's not the envelope that's important, it's the contents.
PDFs are not a specific document type as almost anything can be published as a PDF, so you should use the correct format for the type of source material that appears within the PDF.
However, that is of no help to you because you haven't identified the type of document inside the PDF. You need to clarify if you mean extracts from websites, unpublished material/documents, etc. Only then will anyone be able to give you a definitive answer.