The PDF is what it says - an offline help. It doesn't integrate with the program's normal HTML-based help and needs to be opened manually every time. If you have a computer that is onluine somewhere, you can download the HTML help with the help client and then simply copy over the stuff onto your machine, though.
I don't know what the "Help Client" is. I have PCs online with Production Premium installed. Can I download the file(s) I need With a PC and transfer them to Macs? Is there something that details exactly which files to download and exactly where to install them?
Of corse all of this is preceded by the question, “Why wasn’t I given the whole program (including, obviously, the help files) when I bought Adobe”?