If you want to contact PeterB (or anyone else here on APUG) just click on their name beside one of their posts.
You should see a number of options come up, including "Send a Private Message" and possibly "Send email".
"Private Messaging" is often referred to as "PM"ing.
Click on the option you want to use, and send your message.
If you are asking for a scan of a manual, it is best to send an email address, because it is difficult to send large attachments using the Private Messaging function.