Another thing that may or may not be obvious is hitting F1 is context sensitive. So click on an area in Sonar and hit F1 and it will open the PDF Reference to a semi relevant entry. It's not ALWAYS completely accurate but worth a shot if you want to find something specific out about some weird thingie you discover.
ALSO... another thing that I found out (via scook as usual) is that in my case the Ref Guide was opening UNDERNEATH my Sonar window.
I thought for some reason the F1 manual option was broken on my config but nope. It was hiding behind Sonar. If I went to my tasbar after pressing F1 there would be that "double" icon for Sonar indicating a second window had been opened. Clicking on the second, tabbed Sonar icon brought up the hidden ref guide entry.